You're not being a dufus.
I believe your RME card has onboard "no-latency" digital monitoring, so the latency is only going to be GS3's plus the RME converter latency (probably an additional 2-2.5ms). In other words, the RME card has a built-in digital monitor mixer, just like the MOTU hardware does. It's only when you route the external computer through Logic that you get an additional machine's delay.
You don't need an 02R, since your G5 is functioning as the mixer, but you can certainly use a digital mixer as well if you want to. I personally got rid of mine (a Panasonic DA7) a couple of years ago and haven't looked back. The DA7 is an excellent board - I just didn't need a mixer.
G5s can access a theoretical 4GB per program (about 3GB in reality) regardless of whether they're quads or not.
I believe your RME card has onboard "no-latency" digital monitoring, so the latency is only going to be GS3's plus the RME converter latency (probably an additional 2-2.5ms). In other words, the RME card has a built-in digital monitor mixer, just like the MOTU hardware does. It's only when you route the external computer through Logic that you get an additional machine's delay.
You don't need an 02R, since your G5 is functioning as the mixer, but you can certainly use a digital mixer as well if you want to. I personally got rid of mine (a Panasonic DA7) a couple of years ago and haven't looked back. The DA7 is an excellent board - I just didn't need a mixer.
G5s can access a theoretical 4GB per program (about 3GB in reality) regardless of whether they're quads or not.