So I found an awesome combination utilizing master spells and Miraak's Robes, but I ran into an issue. Whenever I try using Blizzard while under the effects of Become Ethereal, nothing happens. Does this happen to anybody else? I would assume so, but I've never heard of this bug before.

It may have something to do with it being cast on one's self, but the UESP says otherwise. It also says it doesn't hurt the caster, which is complete bull since I always lose HP(the bar shows up when cast), and get the blood splatter show up when I cast. Then there's also the instance where you die if you cast it under the effects of a powerful Fortify Destruction potion.

Also, I dunno if it's worth mentioning, but sometimes the spell would only hurt my PC (as in, the HP bar would go down considerably) when cast and everything else would take no damage at all in combat.

Ya, as it turns out, all master spells with a negative effect hurts you. As it turns out, you can use this to your advantage to trigger certain effects. Blizzard, in particular, makes Miraak's Robes go nuts and begin sprouting tentacles the likes of which have only been seen since the opening of Hermaeus Mora's 18+ manga section.