Re-reading of the whole thread here's my understanding:

1. The church already decided against using the PX-130. Good.
2. The rest of the discussion is just for personal interest on how to use stage keyboards as a sound source when there are long runs to the FOH mixer.
3. The perception of this not being a good place to ask questions is based on several misuses of technical terminology.

a. PX-130 being referred to as a computer; quickly resolved.
b. Grabbing VSTi by a keyboard - I'm still confused by this one, although I think what Amy meant is that keyboards with synth engines on board, can play out audio output in response to MIDI; still not resolved. Amy, any MIDI device that has a 'Thru' connection merely means that the MIDI 'train' doesn't stop at that station nor get modified by that particular device in the chain. In this case, the keyboard that you would want to make sound, must be set to respond to the incoming MIDI data. If you set it as a 'thru' device, then it will sit there silently.
c. Misunderstanding and insistence that TRS connections connote that whatever device attached to them are balanced, when balanced audio merely implies the transmission mechanism.

To answer your curiosity from point 2 above, here is how large churches have typically sent audio to the FOH mixer:

Keyboard has it's own sound engine on board, that was desired in the first place-->analog audio 'snake'-->FOH Mixer somewhere mid to rear of the room.

Many setups now replace the analog audio snake with a digital audio snake, with the A/D happening close to the stage.

Setups with a more modern sound have one or more laptops (and lately iOS devices) on stage as sound sources or even orchestration/timing devices. One worship band that I mix uses Reason software to time their set - they don't have a keyboard player many times, but pads and click track are provided by Reason; pads go to FOH mix, click track to the drummer. This is for a church where most attending don't have church songs known by heart - they are curious about church - and the worship set is pre-planned from a timing standpoint.

I'm curious as to what the church ended up deciding on for the keyboard. If you want flexibility, get one with proper MIDI In/Out connectors(thru is almost never needed for a fairly simple MIDI setup like in most churches these days).

-Scott