Oops, something's different!
Soooooo...I "ordered" some spare Insight parts off another forum member, and at the last moment asked if he could throw in the BCM. Wasn't thinking it would fix anything, but the FSM kept saying that if the sensors were behaving properly, replace the BCM.
D'oh!
Best $20 I ever spent? (Wasn't about to throw gawd knows how much on one from anywhere else just to test it)
So, of course, I had to go take it for a drive to let the battery meter fill up, so the IMA would start assisting, and see what it was like. Night and day! Always a gear higher than I would have been before, takes off real quick, and never struggles...
The 70mpg is pretty sad. Terrible conditions...sooo many stops, sooo much traffic compared to my usual commute time (same drive...went and gassed her up)...but its a good 10mpgs better than it would have been under my usual, more favorable conditions. Looking forward to seeing what she can do more long-term!
Welp...that decided what way I'm going forward with this. Time to ponder the newly opened up options ahead, and get used to how she drives now! (it's a lot different, believe me!)