1. UK has obligations to the EU for the 2020 (already have deals & contracts), other than that they're free to leave. Of course you can just leave and end up with a chaotic situation where nobody knows how trading works, there are tariffs.
Opinion : UK is going toward vassal state status to the
EU by not having a say but still having to follow their rules.
Similar to the other "vassal states" such as Norway and Switzerland.
I'm not sure that the debate here is very sensible or measured.
I think that Brexit is a tragedy, and dearly hope it doesn't actually happen. That is my opinion. But it seems difficult if not impossible to have a reasoned argument about any aspect of it; people are entrenched in their corners.
Well, that depends on what Britain wants. Norway and Switzerland still have to abide by the free movement rules of the EU (which also includes air space regulations btw), and I though that Britain didn't want that? Maybe read up on the EEA's Guillotine Clause [0] to understand the negotiation room that Britain will have when trying to curb free movement.
Opinion : UK is going toward vassal state status to the EU by not having a say but still having to follow their rules.