Thanks for the feedback! I fixed up a few things, and a lot of the other stuff you mentioned is on the to do list.
You SHOULD be able to bring up the help with "?", it works on my machine, but there was an issue that may have stopped that working on some keyboards which is hopefully fixed now. Most of the stuff you talked about is implemented but I can't blame you for not finding it if the help wasn't working.
Enemies give exp at the end of the level, so that you can see what exp you got for killing vs sneaking past(sneaking past gives bonus exp).