2 quick questions i wanna hear your answers to before I talk about my theory

Is Bertram usually armed?  If he isn't, I don't think he could be RJ.  Out of the 6 remaining suspects we know 4 of them are always armed with a weapon.  Stiles and Bertram, I'm not sure about.  Stiles seems to have more body guards and personal protection though.

Why did RJ send Timothy Carter to kill Hightower? or in other words why did RJ want Hightower dead?

I think its Haffner, partly because he's not too obvious but too suspicious either.  In 6X02, he sent the nurse in to ask about Carmen Lee.  On top of that, he wanted to be with Lisbon alone in the room without Jane there.