Machamp with bullet punch / close combat

No. Maybe with DP, but not cc. Sorry for your bad fortune.

Keep it as of now... Just don't touch him for a moment...

Nope, but you can fit 2 CCs before Blissey's Hyper Beam.

I guess he will do ok as prestiger (probably around 1630+ CP) like my 1635 BP/DP and 1620 BP/CC. I don't think I noticed a performance difference between those two. So you might try him out and find out for yourself. Nevertheless, I would definitely keep that one since moves can change. Maybe CC will be the next DP and there might be TMs one day.

Unfortunately do not power up, I've been in this situation it is significantly worse than both C/CC C/DP