1. Yep the guild stuff is actually already done - the guild interface has been completely revamped and includes a context menu for Whisper, Mail, Examine, Invite to Party/Raid, and also Kick for the leader, and rank change for Leader/Elders

Lots of other stuff too. I should have it ready to patch in on Monday.
2. Hmm not sure about increasing friend slots, I think 50 is plenty already.
3. Yes this is probably ok to increase slightly again - I haven't noticed too much overhead from increasing it last time.
4. This I will add for sure - I wanted to get it into this update but I don't think I will have time to fit it in for this coming update.