[habbyguy]

The red flag I see is that the (soon-to-be?) PO put an awful lot of money into a car that he/she decided to sell soon after. That can indicate something is fatally wrong, or that they just got a smokin' deal on something newer and/or cooler.

The timing belt is the biggest issue - if it hasn't been changed, it's way overdue and I would suggest getting that done ASAP after buying the car.

I bought my '04 MDX with 160,000 miles and drove it for about 100,000 miles, and had very few problems. An alternator, a window regulator, vent controller step motor (rebuilt it), and a few other incidental things I've forgotten about (I sold it many years ago). It was the most reliable car I've ever owned (partially because I'm cheap and buy cars with well over 100,000 miles as long-distance road trip cars to avoid insane depreciation from my 7-8,000 road trips).

The PO seems to have done most of the important stuff already - suspension, valve adjustment, serpentine belt, tires, tranny fluid change.

The things I'd suspect could be in need of attention:
The "rest of the front suspension" - primarily the lower control arms, though I suggest swapping out all of the front suspension bits, though maybe not the tie rod / ends.
Obviously, check for rust. And water damage (if you can pull up the edge of the carpet you can often see signs of this).
Listen for a noticeable whine at 50-60MPH, and / or a shudder at around that speed. Both are indicative of an issue with the torque converter, though neither tend to be show-stoppers or anything that'll leave you stranded - just annoyed.
Look for wear on the inside of the rear tires - that could indicate worn rear suspension - or even just a lot of heavily-loaded miles (loading the back heavily changes the camber).

Ideally, you'll be able to check the car for any OBD error codes.

I thnik the 1G MDX is one of the best deals on earth for such a large, capable, comfortable vehicle. And FWIW, mine was perfectly happy to run on regular fuel for that 100,000 miles, saving me a LOT of money (probably $2,500-3,000 US$, which I think is about five million Canadian $). ;-)