I agree with the MoCraft oil and filter recommendation. Solid oil and filter for a good price, good for 5K OCI's which I believe is the max warranty interval, as others have stated. Of course if you can pick up any major brand 5w-20 on sale, I'd go for that as well.
I think that might be more like a half a quart. No I don't think it's a good idea, but then again I'm somewhat of a treehugger myself LOL...just kidding. But seriously, I think that's a complete waste of oil, even if it's $.49 store brand special.
Yeah, but I'd be a bit weary of the condition of the oil when purchased. You say he had to maintain it for warranty reasons, but the fact that it's still running doesn't necessarily mean he followed a strict maintainance schedule. Maybe there's no sludge in it, but for some reason I think it...
I'd Auto-Rx it personally. No telling what OCI's (or oil) the previous 2 owners used. After that then go for it. If you don't want to do Auto-Rx, then you could try syn, but watch for leaks and/or increased consumption.
Me, I'd stick to a thicker 5w-30 as opposed to diving head first into a 40 wt. If you plan on doing extended OCI's and are worried about the oil thickening (which obviously you are since you are planning on Amsoil [not a knock on Amsoil]) then I'd just run what is recommended. I think the VQ's...