So I think most of the problems you have are due to running a Tornado sail with a luff curve designed for a Tornado mast (alu or carbon??) on an Mystere mast with Mystere spreader rake & diamind tensions. Of course the sail will not be shaped properely.

To try to get that sail working better, try tipping boat on its side and hoisting the sail up the mast, but not in the sail track. Then compared the sail's luff curve to the existing unloaded curve in the mast. You want these to be nearly the same. Adjust spreaders & diamond tensions to get them as close a possible, and you're good to go. On the T with carbon mast, we go for a range of 25-55 mm of spreader rake (as measured from the track aft edge to a line or batten laying across the spreader arm tips). Actual setting depends on crew weight and wind strengths). For diamond tension we run a #34 on the newer/black Loos gauge...not sure what this equates to in LBS.

Stiff battens are awful to sail with...sail will be very flat and boat will feel dead.

If you have too much trouble "popping" the main on tacks/gybes...something else is wrong...I'd suspect too little mast curve, giving excessive sail body...but that assumes the luff curves match correctly. This reminds of when I tried fitting a non-prebend sail to a prebend mast...looked horrible and had trouble popping the sail. Slow as hell performance.