I'd like to introduce 1 small concept I was thinking for a while: daily,weekly missions.
So first part - daily missions, are oirented for small groups incide faction,for faster leveling up, one more way to aquire gear and money. It is smth to do, when you don't have anything to do :-)
The point is, in each faction we get new NPCs, who will give random missions, thtat will reset each real day. Other players from same faction have the same missions, missions from other factions are different. Missions are separated into several different classes. When you are done with it, you return to the NPC to get your reward. Rewards are simple- some amount of xp, money, random good loot(druggs, armor, ammo crates etc.). Completing all daily missions awards with aditional xp, money, repair kits.
The mission classes are:
1)scavenging- bring X amount of items Y(chosen randomly from unusable scavenging loot).
2)assignments- complete X type of assignment of difficulty Y or higher.
3)ZC- take control of zone X.
4,5....) your ideas here
Weekly mission are now other story. They are oriented to make some competition between factions, to get some better rewards OR weekly benefits.
Its better start with mission examples.
1)scaveging- bring rare resource X, not so rare Y and a junk Z to the NPC. For X your faction gets 20 points, for Y it gets 10, 5 for junk Z. At the end of week, faction with most points, wins.
2)pve- killing boss X in dungeon, brings 10 point to you faction, completing asignment on sss dif brings 1 point. faction with most points,wins.
3)ZC- faction controlling zone X for longest time (total time during week) wins.
4,5....)your ideas
Those random variables are the same for different factions, so the winer in those missions can be only one faction. So the point is, that if people want to complete those missions, they need to team up whole faction. At the end of the week, all members of the winning faction(even if he didnt do a !@#$) is rewarded. I see 2 types of rewards:
1) material rewards, money xp, loot, but this looks boring...
2) whole faction gets some benefits, till the end of the next week(then next wining faction is chosen), for ex. 35% discount in all shops,double the amount of good stuff in good shop, 25% less winded and supression duration, etc etc...