MOTM

My thoughts:

Switches likely to be used in performance (in order of importance):
PLAY
STOP
SEQ
STEP
GATE1
GATE2

Switches used in setting up (in order of importance):
GLOBAL (major mode)
MIDI (major mode)
UTIL (major mode)
SELECT (submode)

I would group performance switches to the left, excepting the GATE 
switches which I would place close to the GATE I/O jacks. So to the 
left you would have:

PLAY SEQ
STOP STEP

To the right:
GLOBAL MIDI UTIL 
SELECT GATE1 GATE2

Moe