re: 1, IIRC fen tinkered with this after I wrote it. My original idea was that it would rewind you back to the start of the dungeon so you could make new choices, not rewind all of the quest entirely with its timers.
re: 2, this happened due to the way fen reworked the log system. It was disabling buttons based on the log number, not the button number. Submitting a fix that will leave a blank button space for missing logs. Hardcoded, but the whole system is at this point so eh. Seems to fix your issue in testing.