i don't think your layout is quit right. you don't need a set of p1 start / insert coin buttons AND start and select - by default p1's 'start' is 'p1 start', and p1's 'select' is 'p1 insert coin', etc.
if you still want to do it, you may have to configure the pX start and insert coin buttons after the initial setup manually, as i'm not sure you can bind two buttons to the same retropad button during the initial setup.
also your button layout is... weird to me. start and select under the action buttons? bit late to change that now, though :)
i would also have like:
Y X R1 L1
B A R2 L2
since you only have 6 action buttons, looks like you may have to use:
Y X L1
B A R1
however that might not pair well with default controls in arcade emulators, so you may need to reconfigure them after.