If you remove dodge from def then def does absolutely nothing more then give you hp. HP was added to def to balance out def with foc.
right, and right.
However, making HP a stat you can add to is definitely an option... It does add an extra element of character building to the equation. HP was orignally cut off as a stat you can add too because it simplified the core balance concepts (by taking out the need for balancing DEF vs HP). It would make a cool addition to find the balance between one point in DEF vs one point in HP..