Ignoring potential licensing issues, I'll speak to the issue of accelerating RDP hopefully to the benefit of future readers.
Yes, you can speed up RDP in several ways. First, use RDP's own options to remove desktop background, font smoothing, menu animations and etc. Check the "Experience" tab of mstsc.exe. Also, choose the "display" tab and step it down to 15-bit color if you can. I'm not sure if that is acceptable for the application you're using.
You could then use QoS on the network devices that the RDP is traversing to make sure that it has higher priority.
You could also look into hacking the "InteractiveDisplay" option in the registry. Be warned, you could cause some network issues. I'll let you research that option on your own.
If that's not enough, you can use third part acceleration tools. Search for "protocol accelaration" and "RDP" together. Expand Networks makes something that might interest you as does Ericom.