Very simple suggestion:
1) At the Arcaneum vendor, please add every type of primed weapon and armor. Primed weapons currently sell below 50 gp, so no worries about the economy crashing.
2) At all vendors (or maybe Tower of Knowledge only, they need love), please sell all primary ingredients to craft magic items for a reasonable price (e.g. 500-2000 gp). This makes it so you can save up and craft a weapon you couldn't find.
3) Please add more artifact drops to sell to faction vendors. Late game (especially if you make Tower of Knowledge useful), we should be able to hit "brotherhood" status with every faction (if you want).
4) With Sorcerer DLC or Patch, please add pole-arms (halberd, glaive, and maul conspicuously absent!) would be great to have other two-handed options!