Glad you got it running again!
No, there is no specific list of things that will send your H2 database toward trouble. Usually someone's events table is very large, but you didn't respond to the notes about purging your events, userEvents and audit tables. Similarly, rereading, the "db corruption check" that at one point you said helped doesn't do anything to the H2 database, it's a NoSQL setting. You did not respond to my line of questioning about memory in an ext-enabled script. It could be that you're running out of memory.
You reported your log file was empty, but this is almost certainly not so. Can you check the ma.log file (some will have dates prepended) in either Mango/logs or Mango/bin/logs if the issue returns? You may also want to search the existing log files for any memory errors.