I have a few problems with the Inventory UI.

First off, I can't seem to favourite items. Only when in a shop or trading with another NPC. Then I can press "F" to make something a "favourite" item.
However, when I press F when just bringing up the item menu while out exploring, I drop stuff. (Though this is, according to the UI, assigned to R. R doesn't do anything.)
I remapped some of my controls, but this shouldn't be the problem, should it?

Also, how do I access the hotkeys? I can't seem to figure it out. In Oblivion, you just had to press a hokey and click an item or spell to assign it. I can't seem to do it here.

And lastly (though this should be in the Help forum but it's flooded and you end up on the 10th page in just a few hours), I keep getting a strange lag every 20 secs - 3 mins. The screen freezes up but the sound continues. It lasts for a few seconds, then returns to normal. This is mostly out in the Skyrim worldspace, and particularly when I fight or sprint. I've tried to lower the graphics settings and it flows well in 1920x1080, but sometimes this lag just shows up. Any help/advice?

Thanks!