Not a bad brand at all. We fitted quite a few sets when I worked at the dealership with not complaints.
Like said, be sure that the offset is matched, or very close.

I just can't see how pitted/peeling paint would cause a noticeable air leak. How much pressure does it drop a week?

I've had that problem before. My old Probe had the factory chrome rims and at the ten year mark one of the rims would no longer seal. I had it fixed. At the the 13 year mark another rim started to leak.

It got to the point where I'd drop about 5psi a day

Yeah it looks like the +40mm offset is a very common size.

I haven't measured the pressure before filling it. I'll just notice it's visibly low and fill it to 35psi. Today the pressure was way down to like 10psi so I took it to discount tire where I bought the tire to have them check for a nail. No punctures anywhere. So 25 psi over probably 2 weeks is a lot. The service tech showed me how the clear coat was just flaking off badly. 13 years in the salt belt isn't a bad lifespan for rims.

I would have them wire brush it and hit it with bead sealer. Should stop the leak. It will make it a bitch to break the bead when it is time for new tires, but that really isn't your problem is it?

I had a set on my Prelude for a few years. They were pretty nice. Easy to get center caps for also because they're a pretty common brand.

The lower the offset, the more the rims will stick out. If you want them to stick out a bit more, you could safely drop it to like 35-36mm.

I don't want them to stick out. The OEM look is fine with me. I looking for some used 18'' Inifiti rims now.

You, mad pimpin with chrome rims? Did you buy it new?