If we have an onboard laptop on our robot for image processing, can we communicate with the cRIO directly over Ethernet or do we have to send stuff to the driver station laptop for it to forward to the cRIO?
I have not done anything with it, but I see no rules forbiding it. The only thing is that you have to write the code to communicate yourself 
[R53]
Connections to the cRIO Ethernet ports must be compliant with the following parameters:
A. The DAP-1522 wireless bridge is connected to the cRIO Ethernet port 1 (either directly or via a
CAT5 Ethernet pigtail).
B. Ethernet-connected COTS devices or custom circuits may connect to any remaining Ethernet
ports; however, these devices may not transmit or receive UDP packets using ports 1100-1200
except for ports 1130 and 1140.