First of all, I’m happy to hear you are having fun with this! Now for your questions
It’s actually using local browser storage. I should really put a “cookie” consent in place even though I’m not using them. Will get to that shortly.
Hm, well, I can’t guarantee that you will! In normal circumstances they should be stored in your browser, until some event that I have no control over erases them
Exporting and importing saved video’s and cue points are a feature that I had in mind for a paid version of the app if there should be enough people interested in it. Then I can add user accounts and store the data.
As this is just a little hobby project restrictions apply. I’m using a free API key so there is a ceiling to the amount of calls the app can make in one day/week/month. I don’t know the numbers but I think it’s still quite high.