Thanks for the picture, that one is my mod's fault, not the game's: those Animated tab buttons shouldn't be over your character. One thing that would help me fix it: is that an image you exported from the editor, or is that how it looks on your screen?
About the slots: the game keeps 16 main slots and 300 backup ones. Which of those do you want more of? If it's the 16 main ones I'll see what I can do.