OK, this is solely a performance improvement suggestion:

The game engine should be purging assets from disconnected zones (Instances, distant regions) and loading assets on the fly a little better.

I think half of the problem players are experiencing is that the game is trying to preserve every loaded asset, and it can't do it successfully. Keeping only significant assets loaded will reduce strain on the client systems.

I'm not 100% sure that's what happens. Whenever I go back to a huge city after not being there for a long time, it seems that the game has to reload that city and everything in it. Same with traveling to a new region.

Also monsters that aren't right in my vicinity seem to get reduced to nothing but balls of light until a time when i get close to them.

And instances get refreshed every 10 minutes or so after you leave. Dunno what effect that has though.

I'm pretty sure SP is working on performance issues. I've noticed definite improvements in performance since i first started playing.