If you have the app on your iPhone set up correctly and your foscam set up correctly, you can see it from anywhere. The hotels wireless is just a transport option... If not available, it will use your cell service (ATT, version, etc).
Yes, it can be mounted upside down. The internal software makes the adjustment nicely. Including panning left and right. I have two of the cameras hanging upside down from the rafters of my warehouse. Forget about wireless though, highly unreliable.
When you say it's "bad", do you mean that it's not deep/rich/clear (as in "scratchy & thin)? or are you saying that the audio from the camera cuts out?
If it's scratchy and thin, the mic is intended only as a reference and therefore not high quality. if it's "cutting out", then I would suspect a latency issue. Is it bad quality over any medium you use? (i.e. - different computers)
I called customer service and they were actually really good at helping me setup on a mac. Basically the logged into my computer remotely and configured it for me. Only catch is that you can view one camera at a time on mac and mac browsers, unfortunately you can't do multiple camera split screen. For example can't look at 4 cameras at the same time on one screen on mac, only possible on PC broswers. You can however look at multiple cameras through an iPad app or iPhone app. I use Livecams Pro.
The easy thing would be to take out the SDCARD with your recordings on it, and stick it in your PC to play. If you are asking about streaming live video via USB or something like that, the answer is no. It only streams live video via a network connection (wired or wireless).