Quantum Field as Physical Entity?

[Demystifier]

Regarding free will, I'm not sure what it is supposed to mean in the context of physics, so I take it to be the same as "true randomness".

For me, free will is totally different from true randomness. But you are right that free will is not well defined in the context of physics.

Anyway, today appeared a possibly interesting paper on that issue:
http://lanl.arxiv.org/abs/1202.2007
I have not yet read the paper, but I plan to do that in a near future.

Personally I like deterministic frozen block-multiverse, but that's just me.

Me too.

Regarding time as operator: this is something I don't get. Operators are intimately connected with measurements.

Well, if you define operators that way, then fine. But operators are usually defined as mathematical objects satisfying certain algebraic properties, which a priori have nothing to do with measurements.

We don't know how brain works, true, but we don't know a lot about what computers are really capable of doing either (like is P=NP?).

I think we understand computers much much better than the brain.

Regarding time-travel paradoxes etc: if we assume a) 4D block universe and b) that perceived subjective time flows along the worldline in the direction of increasing entropy, then there are no paradoxes at all. There would be stagnation points instead where the entropy reaches maximum. Observer moving from this stagnation point into either direction along the worldline won't remember anything at all, so I guess this would be it for him.

I agree.