How "personal" BF3 servers are is up for debate imo.
BF3 servers are rented from 3rd party service providers who in turn pay EA fees for the rights to rent out BF3 servers.
EA provide zero "official" servers on PC, you play on someone else server or you don't play. In light of that fact I think it's reasonable for there to be certain standards in the running of a Ranked BF3 server and that admins who habitually breach those standards have their servers made Unranked - anything goes in an Unranked server.
I don't know the whole story with OP, but I think kicking players with a hostile offensive message definitely breaches some standards. Even if OP was being just as nasty in the chat box or cheating or whatever the reason was he got kicked/banned, I think as an admin you have to have a bit of maturity behind your decisions.