I haven't put a flat spot on my Neu yet. The pinion came off twice before I used loctite. So far no problems, but I am a basher. If mine comes off I won't lose a race.
I have used a soldering iron to heat the grub screw and then used a pinion puller to get stuck pinions off.
I have the Tower gear puller and it works fine. The only issue is the space between the sides of puller can only fit up to a 13T pinion (tried a 13T and it fit, with a tiny bit of space, so a 14T may work as well but it would be close). Anything bigger won't fit.