Class 3 wormhole question

Hello,

I am considering moving to a c3 wormhole, I have a couple of questions to which I could not find answers on the web.

I understand that a capital ship cannot go through a c3 wormhole. Can it be built inside? If it can, can it ever leave? What if there is a wormhole to a null or low sec, can I jump through it or not? What about cyno-ing out?

What about supercaps? I understand they cannot enter any wh. Can it be assembled inside a wormhole?

Please advise