Wow, Mark! Interesting post! The 12th puzzle is very difficult - it's an easter egg that requires certain . . . well . . . special things! I only know of one person who hasn't needed help to get it!

We have asked for 'clickable' tombstones before, but so far the graves are unresponsive. I think you should be able to 'read' the tombstones (just like in real life - Here lies Lala, a master builder who died in the plague of '07 at the age of 63)!

There are some bugs, as you've noticed, but Arthur and team are working hard to release a bug fix/update to Village Sim as soon as they can!
The game is designed to be open-ended (like all of LDW's games), so even after you complete all of the puzzles, you can still have fun with all of your little people! I find 'peep watching' to be great fun!