MyG37 - 2012 G37S, Sketchy Auction Car

Hello Everyone!

I'm a manual transmission enthusiast with an unhealthy obsession for chasing deals. I set myself on a G37 MT, and I found a clean low mileage one 800 miles away for unsettlingly good price. The dealer specializes in auction stuff, but this is officially a single owner, 24k miles, and has a clean title. I decided that given similar vehicles were going for about $10k more, I'd cop for a short warranty and take my chances. I further increased my risk by going with whatever-shop-was-open-on-Saturday-evening as my inspection source. The drive home went great, but now I'm in the phase of figuring out all the funk that justified the low price :)

Here's the laundry list of things I'm working on:
1. Title was clean, single owner, but was sold at auction and apparently had some front end work done. Whoever did a great job on the aesthetics, but I'm keeping this in mind as I work through all the other fun stuff.
2. The inspection noted that everything looked good, no fluid leaks or indications of heavy wear with the clutch. They did notice that rear tires were the wrong size. The dealer replaced them with ones that seem to be the same as the front if not the the right size. Plenty of tread left, so I'll wait until they wear down a bit and go for something nicer.
3. The A/C lost all its oomph within about three weeks. I recharged the R134a the other day and it's going strong, but I suspect I'll have the problem in a few weeks. Seems like the kind of thing I'll need my mechanic to troubleshoot for me.
4. About two weeks in, the MAF/IAT started throwing codes. P0127 and P0111. When I had my local mechanic take a look they just advised me that apparently it was missing one of the intake filters, which seemed suspiciously related. They cleared the codes and I subsequently gave both sensors a MAF cleaner bath. I'll try re-clearing the code and replace it if the cleaning wasn't sufficient.
5. Also discovered during the local mechanic visit: I have the dreaded massive water leak into the passenger footwell area. I'll be following up on the various cowl and moonroof drain leak suggestions I've found on the forum.
6. VDC light intermittently pops on, stays on until power-off. If anything the fluid is overfilled and doesn't need to be topped off. The pads all look to have plenty of life left and there is no squeal. Debating whether to wait for indications of a pad problem, or to proactively replace the pads.

Anything other frequent issues I should try to get ahead of? Any of these issues you would suggest I handle differently? Advice is appreciated. Looking forward to some worry-free driving in my near future :)