Thanks for the fast response! As far as the X Server goes - i am using RGS on the front end with Paraview and OSMesa on the server side. I plan on testing with RDP today. Our HPC system is headless, so that is why I am using the MESA version.
For --system-mpi, i have intelMPI loaded which is MPICH ABI compatible. It is in the LD_LIBRARY_PATH.
Thanks - any additional pointers would be fantastic!