Here is a version that more cleanly separates the various weapon & crystal slots, and makes it more readable. It also adds a border to the map display area.
Next up is to redo the health & shield display. Our plan is to do a hollow circle for the shield, and then inside, a solid circle for the health display. The circles will shrink and/or fade as you lose points.
We are also working on a re-work of the skills. Our current plan is to have health & shield scale with each level completed, and have the player choose which technologies to learn - Weapons, Cloning and Crystals.
For example: it says 'Left hand' and 'right hand' when you could've, say, displayed 2 transparent boxes to the top-left and top-right (or bottom-left/bottom-right) corners of the screen indicating the items held by each hand. Or even place the two boxes anywhere without any text, and simply have a help screen/manual say what the boxes indicate.
I like your ideas regarding the health/shield redesign. However, I'd have placed them docked at one of the screen edges, and possibly in a corner as well. Also, I'd consider making the health bar a gradient (e.g. red in the low parts, towards green) or making it a solid color indicative of its overall state (e.g. red if < X%, yellow if > X% but < Y%, and green if > Y%)
Weapon stats shouldn't be on display all the time--they consume too much screen space, and they're typically rarely used/consulted. You can display the stats on hovering, or have a stat toggle key, or in an inventory screen (a la Deus Ex)--either way, the default should be: no stats when the player's playing.
Weapon slots are too big, and they're displayed even when they're empty. If weapon slots are going to be on all the time (a la Deus Ex), make them small, docked at an edge, and possibly in a corner as well. If the game offers little in the way of inventory management, you might want to hide empty weapon slots altogether.
I dislike the 'UI rectangle' at the bottom--such a permanent, opaque UI component is useful when you're using it all the time--like in an RTS (e.g. Starcraft). But for an action/RPG/adventure hybrid, most of the time will be spent exploring levels and blasting enemies. Thus the rectangle gets in the way most of the time.
Hope this helps.