Flooring – Jigsaw cuts crooked when trying to rip enginered wood

I don't know why you would've been advised to glue or lock a floating floor down. This a very bad idea & could make the floor cup or ridge if the floor can't move. Parquet is very different in being extremely small pieces with extremely small omnidirectional movement in a whole lot of very small areas.

Having no underlayment is the typical way & allows any moisture from condensation to escape, radiant floor's secondary activity. Foremost, is abiding by the Flooring Manufacturer's written instructions & approvals (over the phone means nothing) above & beyond whatever I or anyone else tells you. Do what the Warrantor says & even file pictures away to back up your by-the-book professional installation.

High tooth count will give smooth results in most cases, but they can heat up in hard wood. More teeth leads to more friction. It's probably a fine all purpose blade, but ripping a hardwood like oak, especially very thick boards, is probably a reason to use a dedicated ripping blade.

Ripping blades have 24-30 teeth, and the tooth profile is flat on top. Some may have a slightly thicker kerf to avoid binding if the board twists or pinches when it's cut. Each tooth takes a bigger bite, but when you're going with the grain, you can afford to do that. Fewer teeth means less friction and heat.