[klevertree]

While I can't address the second point, the first point is something that I've run into a lot.

In my own spaced repetition app [1], I simply space out the amount that people have to catch up on if they develop a huge backlog. For anki, my best advice would be to take this opportunity to delete some of the cards that you really don't need, especially if you're just doing this for fun. Anki tends to be very conservative with how long it makes you review cards, anyways.

[1] https://get21stnight.com/