Chat in this place is generally very low protocol and low play. Its mostly there for what it claims to be - to chat. Very few people seem to care about titles etc, we all chat as we like to chat regardless of status and most seem to have the opinion that an other person may be a Domme but they are not MY Domme and vice versa - unless a specific relationship is in place (in which case, yes, you can call them Mistress or pet or whatever), sub or Dom/me is irrelevant as we are just friends having a chat. Same as a munch or other similar gathering.
Generally, anyone who comes into most chatrooms I have been in demanding to be called a particular title or begging all the Dom/mes to 'dominate this poor sub' will get short shrift from the majority. Most switches I know generally don't switch day to day anyway - it is more a person to person thing. There have been scenes I have been in where a switch is being dominated by one person to dominate another, for example (and in at least one of those instances, I was the sub and I am also a switch... was being dealt with by a Domme while a TS switch was biting my nipples on the orders of the Domme).
So, relax about it and be yourself in the chatroom and see who is there and who responds to you in what way.