Glad you got the Ballon seals on. I was going to suggest you practice on a bannana..

I have never torn one but I only remove them to install new ones. New ones are usually tough enough.
Never tried poly boots though.

80 or 100 is fine. There are lots of new cars that are less than 50. The taper in the hole/stud does most of the work anyway.

I suggest before you put the nut on you take a straight pick and turn the ball stud to point the hole forward to backwards relation to the spindle.
Easier to install and remove the cotter key that way.

I torque them to close to or at the spec and turn the nut to line up the cotter key holes.

Never had a problem. .