Trying to decide if this is worth it for me. Pretty much I only use fireball and flame spam (I dont want to invest too heavily into destruction). I am trying to decide if I should spend some perks here or not based on what spells would be impacted (pun alert)

Runes will instantly kill just about anything and its considered destruction. Its pretty good if you like setting traps.

Dual Wielding projectile spells seems to trigger it. A cheap way would be Firebolt. Also ice shards does the same. I don't think chain lightning does, but it's also much more expensive to cast...so it doesn't really matter.