Remapping I-Pac for Compatability

[Grey112358]

Pi Model 3 w 128 GPU split
RetroPie Version Used: 4.02
Built From: RetroPie website
USB Devices connected: I-Pac2
Controller used: Eventual goal is to be able to unplug I-Pac and attach USB controllers depending on game

I would like to thank this community for all the help, past and future.

I finally have the I-Pac working....2 players w/joystick and 8 buttons each (setup like SNES)

I remapped the I-Pac to make select (coin) the shift key and now Select+Start maps to Esc so I can get out of mame games without a keyboard. I find this makes it difficult to exit libretro games as I assume the Pi sees Esc instead of hotkey Select+Start.

I also now realize that I cannot navigate the RetroPie Setup Menu like I could with a USB game pad because I guess nothing is mapped to 'Enter' on the controls.

Before I start remapping the controls on a per-game basis, is there a better way to map the controls so that I can have full functionality in Emulation Station, Retropie Setup, libretro and the odd emulators needed for N64 et cetera? I need it to be simple for children to use...as in...I dont want one key combination to exit a game in one emulator and not another.