That should have changed in the last patch(1.10), it might put the alcohol in your quick slots, but I have only had it do that when it started a new stack of alcohol. If for some reason I am incorrect about that then just try to keep your quick slots full with weapons.
I would agree about the locked chests but there are a few reasons I don't. It could very well be that the % chance of finding rare items is just that low and the level 3 locks give you 3 times the chance to find an item that is better than common. That change could be as little as 1% vs 4% and with the frequency that you find them its hard to tell. A different argument would be that simply being able to open them increases your chance to find something by being able to open more chests. You don't have to spend 7 points just to get the level 3 lockpicking depending on character, and if you want the things before it anyway its not like there is no benefit to those points spent. I think the main reason you don't get the best items for every one you open is because you could just save your game and continue it just to have a chest be closed again and get great weapons with little effort at all as the chests have static locations and are pretty easy to get to when you know those locations.