Allow people to add gun mods??? Bethesda doesn't control what people can do in mods. Its the capability of the modder. And how do you know that these bugs are in the game already? ITS NOT EVEN OUT YET. Come on, pointless poll. Your poll is all over the place too. "Bug fix" "Arrow Piercing Perk". Sorry but theres lots of polls these days.
But to answer...I think they may learn from past games that they have to do more bug fixes. As for arrow piercing perk...not sure, because i don't think perks are selected like fallout.