What makes Paxton the best trade chip? Seriously. If the Sox trade him to whoever, what would they gain they wouldn't gain by simply waiting for him to become a free agent?
As for Sale, Houck, and Whitlock, I think the jury's very much out of them.
Sale starting going sour way back in 2017 when he struggled in games in August and September. Finally came tommy john surgery, which took a while to recover from--and it wasn't a full recovery--and then came the bicycle injury. This year he looked great for, what, 8 games (a quarter of a season)? Then bam, out for at least two months because his shoulder hurt--Mr. Fragile.
Whitlock has had one good season with the Sox, 2021, all in the bullpen. Last year and this year he's been injured and not that effective as a starter.
Houck has been healthy as a horse and good enough in the bullpen to merit some starts. But he too has been up and down as a starter, especially the 2d and 3d times through the opposing batting orders. Plus this facial injury could affect him psychologically once he faces real hitters.