pixls nailed it right on the head. When I'm playing guitar with it live it's obviously a pre-written track, but when I'm just using the software I'm editing as many parameters that I can think of-Q, solo/mute/pan, even tasteful EQ tricks on the house mixer can help. If you watch videos of an an0va show sometime you'll see that even if a song is "press play and go nuts," I'm still obviously doing a lot of stuff live-because there are a TON of screw ups (unplugged cords, silly channel solos. songs playing on the non-active gameboy, hahaha). But that's okay-you learn to go with those instances and recover! Kris Keyser recently said to me that on-stage errors really can add character to a live set...that's something I'm beginning to whole-heartedly agree with. It's LIVE, be creative-don't be afraid to try something really wacky if you'd like to!
Another thing to note is that I re-arrange parts, edit instrument parameters (i.e. - beef up the mix and/or tighten rhythms), and add transitions that are unique to every live show so far. This ensures that every show is special and it keeps me interested but on the other hand, it also adds more probably to Murphy's Law-but that's what makes it so exciting!
The most important part is that I'm still learning more and more about this with every show I see. There is no wrong answer-if the music is nice, you can do your own thing! Experimenting with external outboard effects is something I also look forward to doing in the future. pixls and I talked about that a while back and it's something that really sparks my interest-time to whip out the guitar pedals!