If websites are able to track their users’ typing behavior and mouse movements, then the websites may be able to use that data to fingerprint, track, and possibly identify their users. Is this a real privacy risk? If so, what are the methods to counter keyboard and mouse fingerprinting by websites? Note that I do not want to disable JavaScript.
I doubt 99% of websites are capable or even care to do this. But if your threat model is that high you can check out kloak. Its system wide and introduces a random delay between key strokes.