Another problem I'm having is that I can't upgrade some weapons and armor to Legendary while others I can. This seems to be the case with the most random list of objects too. Most of my daedric artifacts can only be upgraded to flawless while other can be legendary then some of my normal stuff can only be flawless, like leather armor, while other things can be legendary. Again I see no pattern, the game seems to just pick stuff at random to screw me over with.
If anyone can help me that'd be great.

It may not have to be quite +120%, but that's what I make with Alchemy 100, all the 'beneficial' perks, and 4 pieces of +25% Fortify Alchemy gear.