Damage Increases as HP Depletes & Removing MP from HUD | Willing to pay if necessary

EDIT: Solved. Many thanks to Mr Trivel.

Hey guys.

Not sure how simple this might be to script. I'm using Yanfly's Free Turn battle system, and one of the mechanics I've come up with to balance battles goes like this: 

• The less HP you have, the more damage you deal
• If your HP is full, then you deal normal damage as specified in the database
• If your HP is around, let's say 10%, you do nearly double damage and have a higher chance of scoring a critical hit

I want this to play out for all battles (on the player side only, of course), so it's not a skill or anything like that. If you need anymore info, just shoot me a PM or comment below. I'm also willing to pay if this seems to complicated, but keep in mind that my funds are limited at the moment. Thanks!

BONUS:

I'd also really like to be able to remove the MP bar in all menus and in the battle screen as well. I've found a couple scripts that can do the job, however, they end up messing up the screens entirely. I'm using Pacman's script at the moment, which totally screws up the HUD.

Here's what it looks like now:

Here's what Pacman's script does to it:

Feel free to go off of his script or create your own. 

Thanks so much!