These all sound like nice changes, but could I make a recommendation? There are times when I need to leave a puzzle (phone call, dinner prep, knock on the door, etc...) and I would like to be able to save or pause the puzzle to finish it a few minutes later... Unfortunately right now all I can do is either let the timer keep running, or just close the page.
Don't know if this can be done without changing the "fairness" of the point system - but it might be a feature worth looking into.
Thanks for your consideration in this matter. =)