Thank you very much @Cirion This is a great writeup that should be archived and displayed in a KB or something.
This is what I really needed... I ended up remapping a lot of the stuff but still struggling with retroarch being mapped like you had it.
I use the Buttons1/2 for starts and Buttons5/6 for coins so its really left in MAME mode.
The left *player1 is UP, DOWN, Left, Right arrows... where the right *player2 is rfwg or something like that.... I have it setup to be seen as 2 ipac2 devices too... so I could switch to joystick mode.