I prefer Depth Diggers+Crudest Boots, but I'm also not playing anything above GR30 with my SWK monk. If you think you need the additional CC the Crimson set is fine, but since you have quite decent non-set boots and pants I'd stick with those.
Mitigation trumps life, yes. Go for reduced elite damage.
I'm not sure if i should be using captain crimsons pants/boots combo or my depth diggers/crudest boots.
Also, is 11% reduced elite damage on chest better than 15% life?
Mitigation trumps life, yes. Go for reduced elite damage.