Your's is a situation many of us who record live bands have. There is no easy answer because ultimately what we need is a "overlay" template. A way to mix song 1 save all those settings , and apply it to song 2 and 3 and so on. Sonar, and as far as I can tell, no DAW has this feature.
All you can do is as you've already discovered, is make a blank project that you manually dump the audio into. Or use track templates.
You situation is better because your audio will have to be transferred anyhow. I would recommend using my method#2 Don't transfer all the songs until you have song #1 dialed in.
There are a few solutions, I'll show you the 2 I have used.
Method #1 This works bet when the songs are already in Sonar.
Get song 1 sounding good then I saved each track as a track template naming them.
I then opened song #2 and inserted each track template below it's equivalent.
Now I just drag and drop each original track to the template track and delete the blank oriinals.
method #2
Just import song 1 and get it sounding the way you want, Save it.
Now delete the audio and SAVE AS (and here's what I do), CWP song 2.
You can also use a template. Really the same as saving as a CWP.
Now you have a bank project with all the settings to dump the audio tracks from song 2 into. Save.
Now delete the audio again and now SAVE AS song 3 and so on.
What I miss is for years I mixed down from my 12 Track system through my Yamaha 01v.
It was soooo easy to record a live band, get song 1 sounding good and now all you did was play all the songs through the mixer recording fader moves to midi via the Atari, and sit back and let it roll to the master tape. This results in a great mix for to whole album.
I guess the equivalent would involve using a multi channel audio interface/ mixer like a Behringer X32.