You are probably fairly safe if you are not charging for anything including entry into the haunt. It would carry the same risk as inviting folks to your home for a party. If you are charging then you will fall under your states food handling regulations.
At the risk of offending any of the amazing stone builders here, I would say if you want to learn how to make great tombstones start with the queen of the art Terra. Here is a youtube link. http://www.youtube.com/watch?v=XyfmBL5JuH0 I am sure this is also in the tutorial section.
Married with no children. Long time horror movie fan
Flying, chess and halloween
My love, sweet Queen and noble wife. I alone remain to bring delivery of your pain. Severed my darling, too quickly from this life. Of fires drawn and memories met, I shall hold our two hearts again in single time.