All very good points and well thought out however these are general ways to counter any grab: stop it before it happens, hit him on the way in, intercept before it is locked in etc. , (and personally I think this is better than trying to tie him up and tripping throwing him. There are throws and trips in Chinese martial arts, but I would hazard a guess that the guy who is actively seeking the clinch probably drills throws and strikes from there more than anyone else so it is best to intercept strike and move.)
However my point is that is this stuff actually drilled against the right structure for today environment… is it drilled against someone actively seeking the plum, or against someone who has locked the clinch in and is moving you around and throwing knees or against someone who is locking in a body lock before throwing you or is it simply drilled against structures like chi sao, forearm contact drills and basic hand on the neck defence drills?
In the clinch (if you can’t use the tactics you talked about plus lateral movement and straight power hitting to keep out of the clinch) then you need to maintain your base which is very hard against someone good at clinching: no point throwing knees or uppercuts or seeking the take down if he has control of your balance. Then you need to be able to counter or escape, and I have not seen counters and escapes in the Chinese arts I have studied, nor more importantly have I seen it drilled in the structures and for the situations we have now in the 21st century.
What I mean was that I have been shown grab defences, both against body locks, neck grabs wrist holds etc, but I was never shown them against a proper clinch, nor allowed to spar out of the clinch for round after round to see what worked for me and what did not. In sparring we were reset if it reached clinch range, or limited to pinning/controlling the arms.
maybe this type of sparing and structure was never needed back then in their cultures, (or it has been lost due to secrecy), but it is needed now, you are more likely to meet someone on the street who has seen a bit of MAA and tries to clinch and knee than you will someone throwing chain punches etc.
The only Chinese art I know that does spar over and over in the clinch is the Shuai Jiao, guys and they tell endless stories about destroying other so called deadly Chinese masters in the clinch and with throws