I'm forced to agree that Kruge could've been handled better, in some areas ...
He has this beautiful girlfriend he feels forced to kill off for knowing too much and then just goes about his normal routine. Wouldn't it have been nice to let your Sweet Petunia back onboard, instead? You know ... to kiss up and everything. Especially when his crew is so few, seemingly so delicately balanced, yet he'll kill them off, individually, for mistakes on the job. She could've taken one's place.
Kruge's singularity of purpose, regarding Genesis threatened to push him towards caricature. He killed (intentionally and otherwise) everyone useful in accomplishing his goal. Then, tries taking blood from a stone by beating the living shit out of Kirk for it, when he don't know, for the exciting climax. It almost doesn't work and shouldn't have worked at all, so I credit Lloyd for keeping it all together, by being thoroughly entertaining to watch.