1. I'd say probably about the same, but the laptop will get you 24-bit. If you're sticking with 16/44.1, stay with the JB3 because it's much less hassle all around.
2. If you already have the EMI 2|6, that's pretty good. If not, I'd look for a firewire device first (M-Audio, for example).
3. No - Audacity is free/open source.