I am going to hazzard a guess and say its more of a problem on your end than their end. I do this because, I have been using KR pretty much since release and, well I've never had one of your issues, at least not in months.
The backpack issue usually has something to do with connection, whenever it doesn't load, you're not connected to the server, or having problems. This would most likely account for the missing friends and party members. Thiswould also account for the toggles on your special attacks.
As for your graphics errors, I haven't saw a single one since late Summer, however I could miss them and you should bug report them (ALT+B).
From what I can tell, and my estimate that you were having connection problems more than anything else, and it wasn't the clients fault. And no, it isn't funny.