Yup... Have personal experience with all of the above. Although straightening the crank was done ghetto fab in the toolshed; with mower bolted to angle iron in granddad's vise and a length of schedule 200 pipe as a persuader. Got it within a couple thou on dial indicator without cracking crank or case. Even the old man was impressed I figured that out myself at the tender young age of 12.
I now know I was lucky the crank didn't just grenade the first time I fired it up, of course.
mnem
It's a wonder I didn't kill myself with the damned thing...
Straightening cranks used to be a good money earner and you can get them quite close to perfect and the steel in B&S don't mind being cold straightened.
Even had to do our own but with the move away from one piece blades has reduced most of that sort of crank damage.
Well, I was considering the crude methods used to straighten the crank as the reason I was lucky.
Tho yes, it's true... for 1900s engineering, B&S engines were pretty forgiving of abuse. Maybe because of it.
My plan is more empirical... I'm going to put a new balanced blade on, and if it starts easy like it has done so far and doesn't shake like a belly dancer on crack, I'm just gonna use it.
mnem