As @sdayman said, don’t get pushy. When they get in touch it may not be a polite “do you know you’re flying low”, and could be more “we don’t like your type around here”.
Any form of video is technically forbidden by the terms of service. If it is a small video somewhere on your site it will probably pass under the radar. If you are trying to run a 4K Hollywood streaming site it probably will run directly into the ban hammer.
If this is a commercial site, use a commercial video delivery solution such as Cloudflare Stream. If your site is very popular, is a video streaming site, has lots of large video files etc. then the same rule applies. If this is a hobby site with as many visitors as my personal sites (nearly one per day!) then it probably does not matter.
Anything from Cloudflare replacing the assets with a message through to booting your account.
Yes, but they are more likely to ask you to leave, and serve a warning message instead of your media assets.