So for me to be able to add effects and/or route separate outputs from (say TTS, or Kontakt), I have to create an audio track for each midi track and associate it that way, correct?
Don't make a 1:1 connection between MIDI and Audio tracks.
MIDI tracks just record/playback performance information.
You can have multiple MIDI tracks playing the same Kontakt instrument... or you could have a single MIDI track playing several Kontakt instruments. It's not always a 1:1 relationship.
Think about the scenario from a routing perspective.
If you want to isolate each Kontakt instrument, it has to be routed to a separate Kontakt output (or outputs).
In Sonar, you need to create an audio track for each of these Kontakt outputs.
Each isolated Kontakt instrument can now be independently processed/mixed in Sonar (just like it were an audio track/s).