Im a huge Killzone fan but Shadow Fall is by far the weakest entry since the original! It doesn't even feel like Killzone anymore, singleplayer is a boring slog!
1) I think the servers for Resistance are now offline, not 100% sure on that though. Resistance 2 was dead when I played a year ago.
2) Not sure but BC2 is the best BF on PS3 so im sure its still popular.
3) Still a decent amount of people on.
4) Still a hardcore player base here
5) Call of Duty 3 will probably be a ghost town but the rest are probably still kicking.
6) Not sure, I imagine both are still playable though!