I'm not sure about anyone being dim-witted due to simple grammar or spelling mistakes, but I do know that as soon as I rag someone about it, I'll mess something up in a similar way- usually within my next 5 posts or so.
You could try the direct route and just ask the person if they're any good because you don't have the time or money to waste. Plug in words like "relief", "intonation" and things like that. If the person has a blank look on their face, it's on to the next one.
Idk why, but I've never needed strap locks on any SG I've owned or played. Les Pauls... yes. No doubt, especially on the "top" peg. I guess I'm just standing right with SGs lol.
But, I go with Schallers due to the simplicity of the spring latch thing when installing or removing the straps...
The issues you describe sound more like set-up problems and less like manufacturing problems. The "guitar techs" at GC are often less than adequate and are comparable to Geek Squad computer "techs". Not all, of course, but finding a decent reliable one is rare.
Good luck on your search.
I keep one guitar in open G (5 string version ala Keith Richards) at all times just to have it available. It's pretty simple and there's a lot you can do with it. Changing keys for different songs is just a matter of putting a capo on whatever fret.
I can't vouch for using it on coated wood, but I know it worked perfectly on my 9mm pistol. It was stolen a few years back and when it was found and returned via the sheriff's evidence room, it was covered with case ID numbers, etc, written in Sharpie.
The dry-erase marker trick worked like a...
Another option is to roll up the strap starting at the end enough to tuck the rolled part into the space created by either of the horn cutouts and under where the neck joins the body.
That way it wont be creating any extra tension on the fret board and strings.
I have the same amp and run a LP, SG and a Sheraton II through it. Each one take a few tweaks on the dials to bring out the sounds I want, individually.
It's a decent utility amp for whatever I plug into it.