Yes, the tripod’s head base has a 3/8-inch interface and is compatible with other heads. 

Yes, it comes with a mount which is a plastic pipe with a pivot at the base. I'm sure you could mount the station itself on the same size pipe. The hardest thing would be getting it level. I'm not sure what diameter the pipe is but I would guess the outside diameter is around 1 in. The pipe in the picture is part of the base, and the unit sits over the end of the pipe. Hope this answers your question. 

Perfect for placing in a tree. Easy to install and remove, no trouble securing camera. 

No, they cannot be mounted on a helmet. However, it has tripod threads on the back so that it can be fixed to a tripod.  

Has a 1/4 threaded connection for use with a tripod