do destruction runes ever increase in damage? if u try sneaking will u be detected if u use them? was thiinking of implementing their use in a spell and dagger assassin build but idk...

No they do not.
And since they do very little damage to begin with, I would not even bother buying them.

bummer, they would be kinda cool for a sin if they did like 100 dmg or something lol and all the better spells cant be cast wit ha dagger equipped...

They might be useful at lower levels, but the mana cost is pretty crazy for such a weak spell. Though I do believe it can hit a group of opponents(sp?), and with the illusions Quiet Casting perk you can cast it effectively, I believe if you're going for a spell and dagger assassin that that perk would be extremely worth it, I love it.

I think I saw a bug in the Unofficial Bug List thread that the Augmented Flames/Frost/Shock perks in Destruction don't increase the damage of runes, hopefully that will be fixed at some point.

I like runes because I'm such a spaz during combat that I usually miss with spells like Firebolt and Fire Ball. With runes, I can aim at the ground which isn't moving And don't runes do Area of Effect damage as well?

if you augment your fire, frost and electric spells they get stronger, but they can be plenty powerful, once you're leveled up and have more of an unlimited magicka and you place em pretty par away they can be pretty fun to use in certain situations, and they'll take out multiple enemies, but you need enough magicka to lay down a few of em and augment your spells a bit and take the perk for placing them 5 times farther away and they work good, also take the quiet spellcasting perk, thats a stealth perk, and it works good with runes and all spells really.