I know the prop is gonna 'pop' off of the tapered shaft with a puller and a little heat, but everytime it does, and I know it's gonna happen..... but it sounds like something just broke real bad
Keeping the nut on a few turns is key to preventing a big problem!
This time I followed this post
and lapped the shaft/prop and it's a noticeble difference even in the feel of the fit when installing the prop. When there is a good surface-to-surface contact - you can feel the difference. Checking mine before lapping I had a pretty high area.
FYI - Prussian Blue by Permatex isn't available in NAPA, Grainer, or any parts store in my area. Even called the machine shops and engine builders and no luck. I used a large Sharpie and it worked great.