Malcolm's definitely done it, he said the slab was harder than the roof. He thought the gear was pretty good from memory. I think he said something about needing to put gear into the lip after you've used the hold or something similar though
Gear on Bad Cheques is fine AFTER the crux. I strongly suggest not falling at the crux as that little pocket only holds a dubious wire and you need to use the hold first anyway. Most people lead Strangers Eliminate and then top rope Bad Cheques since the anchors are directly above it, it's the soft c--k option (and that's exactly what I did). It's "top-rope to lead" ratio is about 4000-1 (surpassed only by Dramp). Done on top-rope, Bad Cheques is a fairly unremarkable route though, I wish I hadn't done it this way.