It is funny that you mentioned that item. I use one for most of the things you list except the gun rest. It is especially useful for digging debris out of the irrigation drop box screen and for pulling the moss out of the outlet to the reservoir irrigation pipe. It also works great as a gate opener on the aluminum irrigation pipe so you don't have bend over. Handy tool.
The other tools I find very useful are a fence stretcher and the good old High Lift jack.
