Well, its easy to tell a person is using a tor node if you do a whois. You get a positive for a proxy and the host is usually "tor node."
Is there anyway I can choose to use only a node that hasn't been identified as a tor node, or proxy?
You would have to keep one step ahead of whoever was making the particular list. It would be difficult.
Can I opt to only use nodes for a particular country?
Depending on what frontend of tor you're using, yes. You can select the exit node location.
Can I use tor in conjunction with another proxy that hides tor use? I cant use it with a webproxy, though, as far as i know. Ive tried it and it wont work with this site.
That all depends on whether the particular web proxy allows tor nodes (which, again, is based on a list of *known* tor nodes).
The site administrators wont let you use it if you are using a proxy
If they're effectively blocking all tor nodes and all other proxies, i'm not sure there is much you can do... this site allows all proxies and tor nodes but that's not universal.
one way to be anonymous without using tor is:
http://en.wikipedia.org/wiki/Wardrivingto be super-safe, buy (with cash, not credit card) an external wireless card (usb, cardbus, or whatever is appropriate for your laptop).