There are a lot of quests which can find their way into your journal even though you have no interest in them, and they end up simply making a mess.
So, what I suggest is that there is a quest bin where you can simply transfer all unwanted quests you didn't complete, but can return them to your quest list latter if you want to.

There should also be a spell delete option (there is NO reason for it not to be there).
Even though with the quick menu, hot-keys and stuff, it still creates a mess (not to mention that using hot-keys is broken).
Also, when you don't have any spells in certain school, that school shouldn't be listed in the menu.
For example, when you don't have any books in your inventory, there is no books section in your list when you open the menu to check your items and I believe that same should be for spells.

Also, something about poisoning your weapons; it's pretty bad when you dual-wield!
I can only poison a weapon in my right hand, and not one in my left hand!
How about this?
When I click on a poison with left hand key, a weapon in my left hand gets poisoned, and when I click on a poison with a right hand key, a weapon in my right hand gets poisoned.

These 3 things will make game much better imo and will prevent mess from happening while I do believe that they are not that hard to implement.

Also, remember that comments like 'Wait for mods.' are not allowed here unless you put some good reasons behind that will be considered spam and flame-bait and will be reported.

Poisons need more charges or MUCH less weight.

Not sure about more charges since poisons are pretty lethal already and there is a perk which makes them have more charges already.
Also, I personally never had a trouble with their weight so I can't talk about it.