This would be a massive limitation to the kind of loot you could reasonably equip. There would have to be a much, much greater pool of bonuses on items for this to be not completely obnoxious. Attribute bonuses on items are too generous right now for sure, but this is a matter of tweaking numbers, maybe decreasing the number of slots certain attributes would appear on.
I wouldn't be averse to your second suggestion, requiring at least one actual point invested in the ability for item bonuses. Maybe even something like you can only gain as many points in an ability from items as you have invested (like, you have 1 points invested in thievery, you can only gain 1 point from items; 2 points in thievery invested, you can gain 2 more points from items). This is more relevant for civil abilities than combat ones.
Last edited by Baardvark; 06/03/17 11:07 PM.