I switched jobs on H1B recently and I don't see what you think the leash is. The process takes about two weeks and as far as I can tell there is no realistic risk of losing the H1B even if your (about to be) former employer fires you and the new company butchers the transfer [1].
As a side-note, me changing jobs fairly dramatically increased my salary. I could presumably (I did not negotiate with old employer but a colleague did when he was about to leave) have gotten the same salary at my old place just by showing the new offer. I don't really see where the difference to a citizen is in this whole exercise.
([1] this is so because even if in the worst case you were kicked out of the country you could still reclaim the remaining time on the H1B so the worst case is still limited and I know of zero such cases.)
Valgrind is nice, however, especially with multi-threaded programs the virtualized execution diverges from a non-valgrind-VM run quite a bit so I am not a huge fan.