I must've missed the memo on Whms not being hot for Coil lol.

Debuff on Death Sentence aside, your points are pretty moot.

Aggro really shouldn't be an issue, unless you're massively overhealing or your tanks are bad. Mana can be a pain, but the more experience you get in Coil the better you get there. I can do 1-4 with just shroud nowadays and there's a reason you always got a Bard with you.

There's no reason to make SS an instant cast (Heck, the longass animation prevents it from being anywhere near instant anyway), or having it return Mana. It's fine as it is. Cure III is what needs looking at and changing it into something that at least partially is based on the targets HP% like Lustrate would be pretty neat.