IoTaWatt can measure threephase by one of two methods:

Direct reference, where three voltage reference transformers are installed with three receptacles each on a different phase.

Derived reference where a single voltage reference transformer is installed in a nearby receptacle. Virtually all residential threephase users use this derived reference method with favorable results.
With derived reference, up to 14 circuits can be monitored. You have described 8 singlephase circuits plus 6 threephase circuits for a total of 14. With the mains, the total is 17, so not everything can be measured with one unit.
There are several ways to overcome that limitation:
You can elect not to measure the mains. You can define an IoTaWatt output that is the sum of all 14 branch circuits which should be very close to the main power.
Similarly, you can elect not to measure one of the AC units and define an IoTaWatt output that is the mains minus all of the other loads, which should be very close to the unmonitored AC load.
You can combine each of the phases of the two AC units to measure the total AC load.
You can elect to not measure any other three loads, and IoTaWatt will calculate the total of those three by subtracting the measured circuits from the mains.
To measure the mains, you would need 3 100A CTs. All of the other circuits would use 50A CTs. You would need 11 or 14 if combining the AC units. If you combine the AC units, you would also need three headphone splitters.
I hope that answers your questions.