Can someone explain specifically what function is required for RAV to work with a particular sound card?

I'm trying to record SXM over line input (or mic). I have an old IBM laptop (2008?) where RAV couldn't detect sound. I followed instructions about stereo mix and still no love.

Now, I bought an external (USB) 7.1 sound card that has 2 mic inputs and 1 line input. RAV can detect sound on line input but it can't detect sound using a mic port.

I want to buy a USB sound card that works with RAV that can record both line in and mic. What function should I look for to ensure it's going to work?

And 2 final things:

1) the current solution I have might be OK, but since I've started using it I hear what sounds like RF interference at random times. I don't know if it's the PC, the card, the USB cable, or something else in the office that would cause the interference. If not for that, I'd be OK with the current USB sound card. I can tell this one will take ages to sort out, and when I get the question answered above, I can spend another $20-30 on the "right" card and be done with it.

2) For the RAV replacement product, a) is there a beta test happening I might join, b) any updated word on when it will release, 3) will it be able to capture streams like RAV did before, d) will it actually wake up a Windows 7 machine to record and e) will it have the same sound card issues RAV has today?

Thanks