doing this would render scathe obsolete. The instance in which you have to interrupt a cast to move in the game is fairly low with proper planning at least. I bring this up because of so many people arguing that blm has a useless ability, anyway uses :

Shiva during circle aoes that drop ice on you, if you use surecast those icicles will not interupt your cast

Twintania fireballs will not interrupt a cast during Surecast

T6 Savage when the bees is on you + you are tethered with vines, surecasting here will enable a cast.

knowing that you are about to take damage in excess of 1k that is also physical like autos also warrants a surecast

Not sure how this ability is useless.

Either way I don't think it needs to be changed, blms do fine with dps and are tuned well atm, this could change with upcoming drg buffs however. Anyway, having near 100% uptime on spells would break it (and trust me folks, blms who are really good would achieve near 100% uptime if not 100% uptime if we had 7-10 seconds of unbridled casting available to us on a 90 sec cd or if they leave the cd as is less than that.)

No I do not want one of the things that is skill based to be taken away from my job.