I am playing through again after so many patches and to me it seems 50% or more of the bugs I remember in my first play through are still there. The freezing arrowhead one for example. Most of them seem minor annoyances tho and can be worked around without much fuss. I figure that's why they haven't been fixed yet.
One that really bothers me is when trading with a companion that is not in your party in the End of Time, it will destroy items in their inventory, so the only reliable way to trade/give items to them is to kick someone and rehire, and doing that just to give or trade a few items is kind of annoying.
The stat bug when loading in co-op I don't really remember, but I thought I read it had been around for a while and is a pretty major bug.
Btw I have over 500 hours in this game and would play it again with 100% of the bugs... it is still very fun in my book
(to avoid any confusion as to my thoughts toward this game and it's bugs)