You can already be "connected" with nano studio through AudioCopy/Paste. Both apps support this exchange format, so you can copy and paste from one to another. For Everyday Looper, it's in the AudioCopy/Paste section of the Tools menu.
For your intro/main/end request, as you describe it - adding instruments when going forward in your song structure - you can simply record and merge new tracks.
If you want more advanced song structure, you can use the mute + quantize function. Let's say a part is instruments 1, another part is instruments 1+2+3, and another third part is instruments 1+4. Record instrument 1 on track 1, instrument 2+3 on track 2, and instrument 4 on track 3. Then mute/unmute all the tracks that are unnecessary/necessary for your current part.
A good exemple of this technique for structuring your performance has just been used by TheButtonLoop (very talented by the way !) :
http://www.youtube.com/watch?v=vbrunw7wjx4. For example at 2:00, he toggle 2 tracks to mute/unmute for going chorus -> verse.
Cheers

!