Scott - The process you describe is exactly what we did, to the T.
vxfocus - There isn't a gear 4 on the shifter, so there is no option to manually shift into 4. When I shift into 3 it does just fine, no issues. I haven't tested it beyond that as I was afraid of doing damage.
Here's my plan -
I am going to drain the main pan again and put a bottle of the lucas anti-slip in along with the AMSOIL, fill it perfectly to the top using the same procedure as previously and see what happens.
If the problem arises again, I will try the solenoids. (thanks for that tip vxfocus)
If that doesn't fix it, then she goes into storage...to be seen again....some day. I am hoping the cheap and easy couple of bottles of fluid fixes it up and I don't have another problem.
Everyone keep your fingers crossed! I need a little luck here...