Did he let himself be killed by Thor and The Avengers?

Not sure...Maybe.

yes

Yes.

Yes. I'm pretty positive they made a point of that in the last Siege.

It would make the most sense, since it was too easy to kill him if he wasn't willy to die, I mean the guy rips Ares in half, destroys Asgard after going head to head with Thor, and then Thor manages to kill him with one swing after all of that? Yeah, he let himself be killed.

I think he did.

I think he did let himself get killed.  Otherwise it wouldn't make sense how he could be taking all of Thor's and the Avengers attacks, amped up by the Norn stones, one minute and then be killed by a single attack by Thor that didn't seem to be any more powerful than any of the other attacks Thor had hit him with.  Really, that last attack that killed him would probably have been less powerful than the other attacks he withstood because Thor was no longer being amped up by the Norn stones.  

Yeah  Defiantly 

Yes, but i think his death was fake, im preaty sure he is alive.

Did thor use a God blast?

Yea because towards the end of siege he asked them to kill him and they wouldent, they wanted him to stand trial for his crimes. So he turned back into his void persona Just so they would be forced into killing him