I also have the steam version of Skyrim along with Dawnguard and about 10 GIGABYTES worth of mods and texture packs installed. I am now level 60 with hundreds of hours played and have not had even ONE crash. Well actually there was a crash once but it was because I was minimizing and maximizing into the game over and over, but that doesn't count. The issues are specific to your configuration and specs, sorry you couldn't experience this absolutely amazing game in its full glory.
Get a friend, preferably one with SF experience. Enable the configuration cheat and turn on Turbo and Control Enemies. Start a game on Super and hot seat the hell out of it with one of you controlling the Shining Force and the other controlling the baddies. My buddy just got done beating my secret level forces all while trying to thwart him from grinding off my minions. I'll never play SF2 alone ever again after this amazing experience. If you can't find an experienced player then just tone down the difficulty or set guidelines like no ganking, no spells, etc. A damn pity this couldn't be done in SF1. Anyways, try it and let me know how it goes!