Right, this is my attempt at what I would consider PowerPlay:
In ED, we have two tiers of power: Galactic figureheads, and local powers.
Galactic figureheads are the Emperor, the Alliance head of state (Mahon, currently) and the Fed prez. Players have no influence over these figures or the Federation, Alliance or Empire, only FD.
Local powers are like those found on stations. You can make any of them into a power by getting them 95% influence. Similarly, if your power is wiped out, they revert to system factions. If you want them to come back again, you have to build them up to 95% influence once more. Each of these powers is pledged to one of the Galactic leaders that suits them best.
There are many, much more than 20. Each has its 'ethos', which is described like system powers do in the right hand pane of the HUD. Unlike powers now which have a narrow ethical dimension, having multiple powers allows you to find one that suits you best. Each of these expresses its ethos by the missions it gives you on its BB (see a bit later). So, Archon would get more piracy missions, while Antal would get more peaceful missions (e.g. send 20 new prototype tech to system X).
Each local power has a CG- your job (if you agree with its principles) is to get the CG total to Tier 10. If you get to 10 you 'win' for that round, and you get favourite status with that Galactic leader (also, its worth noting, FD alone would deal with Galnet stories at this level, e.g. Mahon is boosted by power x after they avert a humanitarian disaster).
You increase the CG by completing missions provided on that stations BB. As far as you are concerned, a completed mission == credits. Instead of merits however, each missions influence drives the CG up instead. So high influence missions are more valuable, but more dangerous to do. As described earlier, each power has a tendency to have certain types of missions- military powers favour strikes and fighting, while more peaceful powers favour aid missions (most but not all- you would have the odd fighting / aid mission though).
Sometimes you will get 'golden snitch' missions that are risky, but worth a lot of influence. However, if you fail them your CG influence goes down instead (note, normal missions failed do not lower the CG- so 5th col problems are much reduced).
As your power increases its CG, each reward tier provides small perks: for example, Archon may get a -2% reduction in repair costs at tier 3. Specific power based modules do not exist, the only way to get perks is to work for them each week and unlock the tiers. Each perk is random (but not random enough to fall outside your powers ethos).
At the end of the week, all memebers of that power get a payout based on the tier achieved. For example, Tier 10 gets 50 million each. If you decide to leave a power, you still get a percentage of the money- but: players who defect get nothing!
All powers are ranked: the top power for each Galactic figurehead gets a good reward: money off ships, large discounts and so on. Powers who did not get to Tier 1 are reverted to factions, and must be built up again. You will generate a Galnet story about how good you are, and the losing power humiliated in the same way.
As your power grows, you may find your powers 'leach out' into other systems- these branches can be nurtured until they take over that station. If this happens, the second station has the same CG as its parent. However, you will need double the influence to get to Tier 10, triple for three and so on).
There is no 'enemy' status- if you wish to destroy ships for missions, the bounty system is in effect so for that system (and thus local power) you are wanted.
Merit decay does not exist! You put the work in, the CG goes up each week. There is no penalty for having a break other than less CG activity for that power.
All combat bounties pay market rate, so all kills are graded according to ship size and pilot standing.
I've probably forgotten loads of other things- but this is what I would find satisfying, as it weaves CGs, missions, system factions and ED game mechanics together.