For the cheaper rout you can download the program "speaker workshop" for free and use it with your pc. I believe for your purpose a generic duplex sound card will be just fine. This leaves at problem 1 and possible problem 3. As an Aside, I really feel that this is only a problem 1 type issue and thus you would not enter the rehlm of problem 3.

Theres a link to speaker workshop on my website in the links area if you havnt come across this program before.

Bill