CYeah there should be no problem with it. I don't know the size of your files but I would recommend using a custom domain to take advantage of caching
CYou'd have to use the cache API in workers but it would still work. It is the only way to know if know what files have been downloaded.
CCorrect. Workers run in front of the cache so the only way to cache is with the cache API. A custom domain for R2 will use your zone's cache settings
CYou can stick the cache responses after you have returned a response to the user so there shouldn't be any significant speed difference
