Multiboxers: Dealing multiboxers with kamikaze tactic of "I'll go fight him alone" is stupid. If you're in a bg, you shouldn't be alone. You spot a MB? Call for help, run away, don't face him? Team up and beat the MB 7 vs 5. MB can't do much if you have the numbers on your side, not them. Can't get people to cooperate? Hmm.. I wonder why people MB.. What could it be?
PvE/PvP toggle: Makes things even worse. Toggle off PvP and go farm materials. Nobody can fight you, so you're safe to take your materials, while others may have to fight for it. Can't kill bot farms either when they disable PvP. You can avoid wPvP easily by avoiding few hotspot locations, so why bother with toggles.
Personal loot: Didn't ever like it. Always felt like I was only in for the loots, it kinda destroyed the "be part of the raid" feeling. It just makes loot more about you in a sense. Probably fun for people to get duplicates STS/DBW/CTS/Phyl/TaiaJ/DV/DC while somebody is struggling to get even one.
Modular raids: Nah. Might be hard to implement, and with this client may not even be possible. This would favor individualism/selfishness, don't need loot from X place? Well don't go there, even more so with personal loot. Allows players to skip content they don't want to experience without consequences. Would probably make gearing easier, so GS requirements would increase as well.
It's like trying to fix a thing that was never broken?