Actually I rather enjoyed the rants - nice to see people are human and have feelings.

Anyway, recently had to do same thing - I played keyboard, friend played sax and I created backing tracks for us in BIAB. Songs were all jazz standards plus things like New York State of Mind, Make You Feel My Love etc.

As others have said the key was to make the backing as simple as possible - normally I only had guitar, bass and drums. If piano was there, then I had the volume down low, and/or changed it to a different instrument like a soft Rhodes.

Pushes / holds etc. - yes, use them all the time.

Intros / outros - tried to make songs different by having e.g. slow intro followed by change in tempo, intro with just brushes and piano. Verses we typically alternated piano and sax and then would do verses where we swapped lead for 2 / 4 bars or whatever.

If it's just you playing, then how about using the soloist to generate snatches to play against you? I don't like the long solos it generates particularly, but snatches of a bar or two or 3 here and there can work well. Or on some of them I created (not generated, as I played it!) some solo bits in BIAB to augment the backing tracks.

Cheers
Peter