Thanks for checking in with us first. Here is fine, but in the future we'd suggest asking this sort of broadly-applicable question on the FAQ or, if you'd prefer privacy, on the Mod Contact.

No, you can't RP a thread consisting exclusively of your own characters, and if you did it would not be eligible for base or rewards AC. The potential for infomodding or similar unfair transfers of information/influence/etc.--whether accidental or intentional--is just too high for us to allow this. For the same reason we also ask that players do their best to avoid having two characters written by the same player appear in the same group thread. If that can't be avoided, then the two characters should not directly interact, and only one can use the thread for AC.