Proving fair use is legally complex, and to be blunt it is very possible you are incorrect - in any case, it is unlikely a lower court would judge on it at all given the complexity rather than referring it to a higher court (note this is a generalisation as parent doesn't identify the territory they are in, but it's a reasonable one).

Also note that YouTube's ContentID process is not a DMCA process. It is a privately negotiated system that YouTube have come to a commercial arrangement with various rightsowners in order to minimise their legal liability. You have no come back against this, because they are not DMCA notices at the first stage to be improper.

If you want a video hosting service that is going to have your back on this then you are probably going to need to use one that is more expensive than free, and quite possibly demonstrate that you have indemnity insurance.