Dythim

nevermind

The Elder Scroll you sell to Urag gro-Shub is needed for the Main Quest line. After you complete said quest, you'll get the option to sell it to him.

Just to clarify, the game crashes if played in its original state (vanilla, no mods installed)? That's heck of a lot of mods that can be conflicting.

If your using a custom race, Skyrim doesn't like it. You'll need to check the mod if it has a vampire patch for it. Or you can download this mod: Better Vampires and click on the custom race option. For whatever reason, this problem also happens for vanilla races for some people (me included). To solve this, you'll need to download the above mod to fix this as well.

Jesse, may i suggest using this mod Stones of Barenziah DROPPABLE plus Quest Markers or Stones of Barenziah Quest Markers. I used to use the console commands until i found this mod, eliminated all the hassle when creating new characters.