1) GUIDs are a terrible design choice - fat and fragmenty (coined a new term there)!

2) no wonder your updates are getting slow - look at how many include columns you have in those indexes! You cannot have you cake and eat it too - either you accept lookups and stop including so many columns just to get a covered index or you suck up the blocking/locking/performance hit of maintaining so many fat indexes.

3) BTW, did you perchance use Database Tuning Advisor to derive those indexes??