To answer this question we need something like a formal definition of "free will". The position on LW is generally that no such thing can exist, that the concept is confused and that the question "do we have free will?" dissolves into "why do we sometimes think we have something called free will?"

If "free will" is meaningless, so is "feeling of free will", etc. Consider "feeling of vubbleflox".

First I'm going to assert that determinism isn't free will, and randomness isn't free will either.

It's uncontentious that neither pure determinism and pure randomness is (libertarian) free wiil. However, some libertarians theories (eg Robert Kane)'s rely on mixutures of determinism and randomness.

The free willers can just change their definition so that people's behavior can be divided into a causal component and a random/uncorrelated component and still there's room for free will there somewhere

As noted abve, that has sort-of happened although no change of definition was needed.