Hi BD
To check the chain you look for longer sections of it, than pull from the chain in the middle of the rear sprocket if you can see a tooth change it right away and also if you have to readjust it in 600miles or so I would change it.
To change it you need a riveter/braker and a vernier or...
I see crap like that on bike frames all the time, cold mig welds was a kawasaki specialty a few decades ago, not very satisfied with the welds on my gen 1 either.
you say that's titanium? it looks more like stainless in the picture + titanium is mostly tig welded... maybe that's another thing...
buy a can of contact cleaner and spray all the connectors you can find, take the right black plastic cover(the one for the fuel pump, there is one connector for speed or rpm (don't remember), also under the tank there's a bundle
I mounted a few on some cruisers... hard like a rock and needed a ton of weight to balance the wheels, cheaper than the cheapest though.
Funny it says Full Bore USA on them, but it should be fullbore CHINA, they even have USA flag(colors) on the sticker
so the G9 cradle/speakers work with the G4?
I'm satisfied with my G4, have cradles in 2 of my helmets, One speaker was bad from new but I replaced it with a speaker from some headphones I had .
Q series is lower end, a buddy just bought one and we paired after half hour struggle but I couldn't...