pros/cons of welding hitch parts to frame?

[myredracer]

I am considering getting the snap-up brackets for our hitch welded to the A-frame. We really would like to install a tongue box for storage behind the propane tanks and I found one that will fit perfectly if the brackets are not bolted to the frame.

Are there any good arguments against welding to the frame? Does this create potential weakness in the frame (from heat) that could lead to cracking in the long term? Stabilizer jacks get welded to frames all the time....

Am I correct in guessing that frames are powder coated nowadays? If so, what touch-up paint is compatible with powder coat paint? Or can any suitable paint be used to cover the bare metal and to prevent rusting?

Am also wondering about the brackets for the dual cams. They are normally bolted on to the side of the frame with self-tapping screws from what I can tell. I have to wonder if drilling holes in the frame could possible allow water to ingress into the frame? We get a LOT of rain around here. I am wondering if welding these on might be an option?

The biggest reason I can see why not to weld anything on is that it would be permanent.