Don't think stickmount does what you think it does. It allows an android device to mount a usb stick, it doesn't export the onboard resources as usb mass storage.
But if you root, and if the Nexus 7 does support USB OTG, yes the combo somewhat fixes complaint #2.
2.4GHz saturation is just about anywhere now. I live in little a podunk town and here in the downtown area you can see scads of access points. From home I only see three to six. Products really need a warning label when they claim to support 802.11n and don't support both bands.
Good to know about the gps, seen conflicting info online.
After seeing the iFixit teardown I feel a lot better about the disposable angle, of course it won't mean much if there aren't actually a few sellers of spare battery packs in a couple of years. Which is always a problem.
Still leaves the big ones. No SD slot and no easy way to even access the onboard memory from a Linux box. So no easy way to put content on except via wifi. Bleh. No easy way to develop alternate firmware since you can't just boot from SD. Adding an SD slot wouldn't have cost a dollar and the lack of Mass Storage is purely a software issue.