Pigeonholing Phoenix has always been an issue with the game as there are many aspects to it and quite often one can be seen to dominate or for some people, not being interested in one aspect leads them to neglect it - sometimes to their detriment.
Each of the five aspects can be seen as the five points on a pentacle, each interacting with each other and all being affected directly or indirectly by the Game Master.

Combat.
For wargamers, this is often seen as the primary purpose of the game - to be impregnable to attack and to be able to hammer enemies with impunity. Combat require the construction of machines of war and troops to use them.
Construction of war machines - tanks, warships and their likes requires technology and bases, which fall into the colonisation category.
Troops, the underlying strength of this position require paying - paying however requires stellars and invariably come back to commerce or 'protection' money through alliances or treaties, aka diplomacy/roleplaying.

Commerce
There are two general means of earning stellars, collecting it directly from civilian populations or by dealing with other players.
For those interested in amassing wealth directly from civilian populations, they need to find somewhere where there is a civilian population that can be exploited through merchandising and for extra wealth, finding goods that can be sold to the civilian population.
In many cases these civilian populations are in regions of space claimed by other factions and colonisation of the world will require some level of diplomacy with the other faction. Further, goods to sell to the civilian population will have to be found through exploration and the base from which to sell the goods will have to be constructed (colonisation).
Even if it is decided to only deal with other players through commerce, often resources will still have to be found through exploration and private deals will also need to be struck (roleplaying).
Acquiring ships to conduct the trading will also require some level of communication with other members of the faction or through private deals and once some success has been achieved there is always the question of protection against pirates and defending assets from potential looters (combat).

Exploration
New star systems, virgin territory exists for players to discover, it is just a case of extensive research into subspace and adjacent unknown space. Some of these systems may already have civilisations present that are just waiting to start trading.
Exotic trade items resources could already exist right under the foundations of a base, just waiting to be discovered.
As well as exotic trade items there may be ores spanning the entire range from basic elements right through to super rare minerals. These might reside in the sub-ice of asteroids or the atmospheres gas giants.
As well as discovering minerals and trade goods, there are new sentient species to encounter. How these are dealt with (roleplaying) may well determine the future relationship between the sentient race and the faction. More than one promising relationship has turned sour through a wrong-word.

Colonisation
This covers everything from building bases through to designing ships, researching technology, producing ordnance and other components for industry, recruiting personnel and even improving a planet's commerce potential.
Obviously such a large area often requires somewhere suitable to build and can often require some serious negotiation with other factions (roleplaying), not to mention resources (exploration). Then there is the question of defending everything you have built. While it is not always necessary or even practical to be impregnable, it is always a good idea to be less inviting for attack than other potential targets. Whether this is achieved through ordnance (combat) or treaties (roleplaying) is down to the faction.

Roleplaying
As can be seen from the above descriptions, roleplaying in the form of diplomacy, treaties, support from civilian populations or even threats and bluffs, plays a vital part of the game and one that can be overlooked from time to time.
A combat oriented faction for example, still draws at least some of its revenue from civilian populations. It may also trade or have colonised locations where its navy might is stretched thin. Smashing an enemy on a world that is intended for colonisation also tends not to go down too well with the civilians, especially if they are not forewarned.
An exploration oriented faction may miss some of the best resources simply because they never dealt with the primitive tribes and drank their hoo-doo juice.
A commercial faction may have their merchandising embargoed because others have been spreading lies about them in civilian circles.
These can be weakness to exploit or holes to plug. Realism and circumstance play a great deal in exploiting this aspect of the game - populations are won over slowly and often sacrifices are required to achieve success, but the effects can be crippling especially where there is a 'special' relationship between the civilian populace and a specific faction.

Profiles
Affiliations - factions in which players control assets - all have profiles. These can be 'carved in stone' or mere guidelines. These are taken into consideration during GM Moderation when determining results. A faction that has a profile as a bunch of cutthroat entrepreneurs are unlikely to gain any support from a civilian faction, but by the same token, are unlikely to have their merchandising suffer when they fail to take a strong stance on a moral issue, pleading 'nowt to do with us'.
Empire style affiliations have the most to gain from loyal civilian factions but can also suffer the most when they fail to roleplay to their profile. Loyal civilians have expectations.

Game Master (GM) Moderation
The role of the GM is to facilitate the continuous progression and expansion of the game. As well as dealing with the mundane such as answering questions and pressing buttons as part of the daily running of the game, the GM also writes specific results to explorations, investigations and special actions. Finally, it is the GM's role to expand the game universe through developing plots, new regions of space and adding new items to the game.
Special Actions are what separate the game from a typical online/computer game. The GM will interpret the submitted special action and give a result. The nature of the special action is limitless, though obviously some degree of circumscribed reality is applied based on the current situation in order to keep the results believable within the framework of the game. For example suddenly declaring that the explorers are gods during first contact with natives will not result in millions of people across the entire globe suddenly falling on their knees in adulation - it is assumed that the larger the population the greater the diversity of thought and an ever increasing level of suspicion, cynicism and/or analysis of the facts.

Zones of Moderation
Moderation can generally be separated into three broad categories. These can be applied to regions of game territory - generally star systems, but potentially just the starport of a base or an entire cluster of star systems known as a Periphery.

Open
This is the most common zone and represents what can be loosely classified as a hands-off approach by the GM. Intervention is largely through reaction to special actions that draws the GM attention to a facet or detail in the game in an attempt to elicit some sort of response. This might be to point out to natives how bad the owners of a starbase on the planet are and give suggestions how they might alleviate the situation or aid the instigator of the special action.

Protected
Protected zones are ruled with an iron fist. They are there for the benefit of all and are something of a nursery where all can exist without fear. Actions intended to harm, even through carelessness are punished by the GM. Initially these may be little more than a stellar fine or the damaging of the offending position in a Pavlovian conditioning manner but will quickly escalate to wholesale slaughter is the recipient of earlier warnings proves either intractable or proves incapable of learning. The GM is at liberty to use whatever means to restore the status-quo, up to an including the removal of all offending assets of the transgressing faction from the zone - explosively if necessary. Actions that exploit transgressors of the protected status through non-combat oriented means are likely to prove especially successful just to emphasise the point - this is a protected zone. The Yank star system is the prime example of this - though it does include EEM assets.

Controlled
This is the middleman between open and protected and is generally regions of space where conflict is limited. Generally speaking there is a charter or explanation of what can and can't be done within the controlled zone. This might be limited warfleets, limits to the amount of bases that can be built or the nature of the actions that can be conducted within the zone.
Punishment is less severe than in a protected region of space and is generally meted out as a result of escalation or repeat transgressions. Carelessness or transgressions are rarely punished on a first offense basis unless they are magnitudes over the designated acceptable limit.
The Halo periphery is an example of this kind of zone.