Since Dimension Door and MP regen should be interchangeable spells

Even this thesis is doubtful. A mechanic like "either one spell or the other per day" is just oooooh very clunky. It's a crutch for online play, not classic, and just overall wrong.

And, I repeat, figures like 1900++ moves per day cannot be seriously considered; it's essentially a second turn, too strong a bonus, Water will become a must-have.

That is to say, the idea of gaining additional moves itself is interesting, but it needs to be implemented differently, either in terms of numbers or mechanics.