Nope, numerous countries make trade deals with the EU while not being members or falling under the primary jurisdiction of EU institutions.
In reality, we will not be on the path to ever closer union and we would always have limited influence when the majority want to go in a different direction. Sorry if this is news to you.
Nope, that's not news, it's mere speculation.
What do we actually get by leaving that we couldn't get by staying - in reality?