I can imagine downtube shifter bosses getting in the way. Perhaps a front derailleur boss. But your frame has neither.

The rest all seems to be minimal bumps that I'd leave alone, although personally I wouldn't be using the pump pegs as they are, so I might consider removing those, but might just leave them as a unique bit of history.

I'm surprised that frame has top tube cable stops. Are you planning on using brakes? Again, I'd just leave those in place in case you chose to do something different.