Mech build question

3rd job: leave rocket punch unmaxed. There's almost no mech out there that finds any reason to even have it key'd anymore thanks to lvl 1 laser blast. Even on a big wide map where you'll be in prototype mode, you'll be doing a mix of drill rush and atomic hammer more than using punch. Hell after moving some mobs around you might consider switching to tank mode if they have a buttload of HP (compared to your damage) or if they dont.... they'll go down by using only hammer. So punch really gets no further use.

I never once used rocket punch to train, even before I was 4th job. I know several other mechs that didn't use it either.