Hello again cynosurex, sorry for the delayed response. As mentioned in my response on Monday 1:10am. This has already been designed and product tested (by Tactical Designs). I have field tested their design but unfortunately it doesn't accommodate new and very popular carbon fibre paintball barrels that are 1inch in diameter (and I couldn't get them to produce a 1inch version).
The key features theirs has is the thin wall clamp (that wraps around the barrel), making it unobstructive (since the player aims down the side of the barrel), and the offset design for the camera mount (giving more adjustability when mounted forward or backwards on the barrel, although this is not as important as the clamp thickness). I know your big concern is the clamps wall thickness, which I measured "0.0760. The material Shapways uses is impressively strong and flexible, exhibited by this clamp I have stretched the split opening to slip over the barrel with no signs of fatigue, or snapping, or cracking! One thing that would improve Tactical Designs design would be to lengthen the clamps width. It's currently ".03935, and if lengthened to ".060, it would help stiffen the clamp.
I can guarantee a good selling point for this mount which is very appeal-able for popular carbon fibre barrels made by Planet Eclipse. No one has a mount for this barrel yet. I myself need at least 3 of these. If you choose not to do these improvements on this for me to try out, I will still give your latest design a try.... Thanks Very Much, and I appreciate your help!!