Holy crap, my friends!
I leave for a few days & I come back to this! OK, OK, I get it. And the Stig mystery goes on.... :)
Guys, the bike runs, acts, corners, et al, now. It wasn't the 'geometry' that was screwed up. It was the front tire along with a bad left front bearing. Now I can slow down at any speed with 'no hands' & it's steady as a rock.
The 18" rear tire (standard size for wide custom tires) makes absolutely no difference in the front end 'geometry'. We had all that math done BEFORE we did any mods. The 'slight' lowering (front & rear) and 4.5" stretch also did not have any significant effect.
The bike is tailored to my method/style of riding which is 'medium' aggressive. I really don't push it that hard on the public roads. The street is just too unpredictable.... deer, gravel, oil, chip-seal, chickens, barb wire, etc.
The biggest difference in riding with the wider tire is if I trail brake a bit too much, the bike will 'pop' upright. Probably due to its less radical profile.
Anyway, thanks for the comments. I'm just old sportbike wannabee. :)