Oliver- actually is an INFJ, but puts on a ESTP persona when he's out and about, not being the vigilante. I say INFJ because he screams idealist, Ni supported by Fe, and he is organized in his pursuit.
Laurel-ENFJ-she even says she's and idealist, and seems more E than I to me.
Thea-ISFP all the way.
Felicity-INTJ (love her btw)
no idea on the others.