don't want to get interrupted outside of surecast or equanimity?

Get a Pocket Healer SCH- you can cast for days. (Aldoqium, Succor, Fey Glow).
If you're annoyed of BRD hitting you simple just move back the farther away your go the less damage they do.
Pro-tip bait them further back into your team. then kill them, pretty simple. Sleep/nightwing/manawall/surecast/equanimity/Lethargy/Swiftcast/Blizzard(Heavy)/ Ethereal Manipulation to a members.

You have plenty of tools utilize them. And i know they're annoying but smack em in the mouth when you see them.

My job is done.