Depends on how you value the proc. If you are going by straight up uptime then resto druid is by far the best, and feral druid is definitely above survival hunter regardless. Boomkins overtake spriests at higher gear levels also.
No. Even on a single target fight - a shadowpriest and boomkin have 100% uptime for DI - a resto druid only has 100% uptime when they are multi-hotting - which means for many fights where raid damage is big but sporadic, or the fight is about tank damage - a resto druid is worse than either of the dps classes even for uptime. In terms of who gets the most personal dps - and who benefits the raids overall dps the most - it is a shadowpriest until full BiS gear on both a spriest and boomkin at which point they are Comparable (not better than shadow), and thats for single target scenarios only - for multi-target scenarios always the spriest.
Survival hunters are way better than feral druids for uptime on multi-target fights where they can cleave serpent sting - but on a single target fight I agree a feral should be better than a survival hunter unless I'm missing something big about survival play (but I have an 85 hunter so I doubt it). This is an almost irrelevant point though because:
All other dps classes are terrible choices by comparison to shadow/boomkins.