Maybe if u make friendslist flip pages...like 50 per page))) less lag then)))

I got also nearly 500 friends...well u join a game/host a game,and either u add the host...which makes +1 in fl or if u host ppl add you which is usually +3 ppl in fl....

Guild members cap...well guildhall can fit ONLY 25 ppl at once...

I think 250-300 ppl per guild is ok...timezones and etc...its too rare that all members r online simultaneously