Out of the 50s you listed, only FB, Vizier and Royal Guard seem like definite 60s in my view, the rest should be fine to leave at 50. Peydma, Zargala and Nazana are definite 60s as well, as are your new pulls Skullcrown and Belanor. As to which ones first... I'd say Peydma, Zargala, Skullcrown probably, given that you already have two great supports at 60 but still need more offensive debuffers/nukers, while FB, RG, Vizier are a bit more specialized/endgame champions. 

Do you have any hero's who can do Crowd Control (AOE Provoke, Stun, or Freeze)?

zelotah (doesnt need books)

I do have Alika and Arbalester and I think I have terror beast too, then I have hurler, are these really helpful, should I level them to 6*?

Which ones do you think are excellent ?

I also have jigglehunter, should I max him out?

The heroes you listed don't sound like the right heroes I was talking about.

I wouldn't 6 star them.

Do you have Gnarlhorn or Umbral Enchantress by any chance?

Yes I have Gnarlhorn, will start leveling it up.