I've recently put together a new character that is more or less a pure thief, but as I level up, there are opportunities opening up to add certain elements to its makeup. The first thing I did was add a Telekinesis spell to augment the theft characteristics. However, since this is a sneaky thief, I'm also thinking about opening up the Destruction school specifically to use the runes as traps. I noticed that Destruction spells can be made more powerful with "Augmented Flames" (etc). I'm also wondering if Dual Casting makes the Runes more powerful. Does anyone know which perks would be required to get the most bang for the buck on Runes? 50 damage isn't much, so I'm trying to up this (I've even considered hitting an enemy with a poison that makes them weaker to magic/fire before they hit it.

I realize that Runes are not going to do a lot of damage to some of the high level enemies; this is purely to satisfy my need to add skills that complement a Thief/Sneak character.

Dual Casting does make Runes more powerful. The standard 2.2x damage for 2.8x cost. However, Augmented Flames does not make Fire Runes more powerful. So only perks you need to use Runes to maximum effect is Novice Destruction, Apprentice Destruction and Runemaster. Add Dual Casting if you want to.

I use Runes a lot. If you cast one somewhere before the battle, it's free, because magicka regenerates super fast out of battle. Runes are a lot of fun for kiting a melee opponent. Just keep running away and cast runes in front of you as you run.

I personally did not find Telekinesis to be useful for stealing. But if you are roleplaying, that's your choice of course. I'm always looking for new useful ways of using underused spells. My favorite thing to do with Telekinesis is for locating and grabbing dragonflies after you kill them with Fus. My dragonfly catching rate is near perfect now.