The values were assigned with the assumption that their limited range would be balanced out by the assault advantage, so damage should be the same as the equivalent rifle type.
Your values are fine.
Speaking of points costs, I have been pondering that maybe the low end of the points scale needs to be wider, to allow more/better differentiation. Trying to fit all the infantry into, essentially, a 15 or so point spread is a little tight.
Nordic Weasel Games
I am not that great at seeing the wider implications of points changes but as a general thought yes inexperienced and demoralised troops are very fragile. A widening of the gap is certainly called for. Being wary of making it so big a horde always wins. A two point gap between light and medium seems too low to me. Probably 3 or 4.