Re: wheel spacers
Pure spacers can be death traps, many a cars have busted all the wheel studs off from spacers. The two its like a washer, it allows the rim to slip position on the hub and puts the studs in a different type of stress that is more likely to break them.
That said, they seem fairly common around here and no real horror stories that I have seen. I would at least make sure the wheel studs are good, maybe even replace them with high strength ones if possible. Studs are not too terrible to replace, and only cost a few bucks. Cheap peace of mind.
I would NEVER run a "spacer" that was an inch thick, or even 1/4 of that. But a 1" adapter can be done safely.