I'm level 9, and one of the minibosses was a Draugr Scourge. The others are mostly Draugr and Restless Draugr. But those are in the first part of the dungeon, then you zone into the boss area / chambers.
The more I play and look under the hood of Skyrim the more disappointed I am getting. Looking at several youtube videos you learn that alot of the perks are useless, misleading or outright broken. The magic, as mage build, is pretty much pointless since damage doesn't scale up, thus making a mage player weak in the end... so magic is just a sidekick thing to melee.... and now this whole boss scaling being totally bats.
Sigh...
Then just play on Novice. Or take along 30 health potions, or learn how to conjure an atronauch, or etc.
The game is too easy, not too difficult. Only 3 or 4 times in some 8-10 characters have I ever had to turn the difficulty down from Master because I was getting killed too many times in the same place.
Get some better armor, weapons, up your skill level, go get the Wabbajack and bring Lydia up to your level. Or go to to a tavern you've never been to and hire a follower so that they're at your level. There are a million ways to improve quickly in this game. Especially at something like level 9. You should be able to hack your way through wolves to level 12 in about 45 minutes.
As for playing a destruction mage, it's very possible. You just have to couple it with enchanting and alchemy. Find destruction cost reduction enchanted item and disenchant it, find article of clothing/armor. Enchant it with destruction buff. Rinse and repeat over and over until you have around 75% cost reduction for casting. You'll have a powerful destruction mage, even on master.
My last mage had 100% reduction and she was unstoppable. On Master. So it can be done. It just takes some effort.