My suggestions are:
1) Don't use Happ Ultimates.
They are the worst joysticks Happ makes.
For the 8-ways, Supers or Comps are a better choice, if you want Happs.
The Ultimate 4-way just uses a smaller actuator, so that you can't hit diagonals.
This makes the stick feel and perform terribly as a 4-way.
The Reunion sticks would be a better choice from Happ for a 4-way.
They have physical restriction.
My personal choice would be to use a single 4/8-way, rather than the two that you have.
You can remap Q*Bert and Congo Bongo to use the diagonals of the 8-way as their directions.
That would leave you room for a trigger stick in place of the other stick.
2) Get a TurboTwist2 for your spinner
The spinner you are showing is an Arkanoid spinner, and will work good for Arkanoid, but not much else.
They stop when you stop, so you can't give them a spin in Tempest, and get them to continue moving.
3) Move the Exit button
That is going to get hit accidentally very easily.
Nothing is more annoying than having the game of your life stopped short by someone hitting the wrong button.
4) Double-check the location of your mouse buttons
Are you going to be able to use the spinner without accidentally hitting the mouse buttons?
You don't want to have to remap all your applications to ignore the mouse buttons.
Two suggestions for this are to connect 3 of your player buttons to the mouse buttons, or move the mouse buttons above your P-1 buttons.
5) Reconsider your P-2 coinup
Do you really want to have to coinup the other player all the time?
6) Admin Buttons
I personally like all my admin stuff on shifted P-1 Buttons, with P-1 Start as the dedicated shift button on the I-pac.
That let's you have access to all the same functions, but without the extra buttons on the panel.
A dedicated shift is a great option if you are planning to have alot of parties.
That lets you disconnect the shift button for the party, to keep people from messing up your settings.