Couple questions from somebody who just downloaded
 

So I just downloaded LUI and started messing around with it. I like it so far but I got a couple snags on stuff I am having trouble changing.
The first thing I don't understand is: why when I open my bags it says I only have 4 bag slots when I know I have 5 bags?
2. I put all my action bars out and made them bigger but now my casting bar is covered up. How do I move my casting bar to somewhere else?
3. Is there some setting inside LUI to change the key bindings for the action bars or do I do that through the standard wow key bindings?
If anybody can help me with this stuff I'd really appreciate it!

There is some weird issue with bags that was introduced with 5.1. Occasionally when I hit B to open all bags I will only see 4. I have to mouse over the "missing" bag and click on it to get it back. I noticed this on a character that uses Dominos bar mod, and also on a char that doesn't use any bar addon at all.

As a temp fix, if LUI has a "one bag" feature, you might look into turning that off if possible so you can see all of the bags.

You could also check the official LUI forums which are accessible from the LUI main site.