Undisclosed,
That may be a problem with Pelco. Their keyboards use Pelco 'P' protocol, which is at least somewhat proprietary. I've heard from a number of sources that it can be difficult, if not impossible, to interface with CM97xx matrix system keyboard interfaces.
A better solution for PTZ interfacing with two separate systems could be to use "code merger" units, like the Pelco CM9760-DMR or the Sennnetech SCM-200-Pelco or SCM-800-Pelco. They would allow multiple control devices to control a single daisy chain of PTZs.
As far as sharing video between an analog and an IP system, it would depend on the cameras. Analog cameras can be looped through the matrix to the VMS' encoders or vice-versa. IP MP cameras would have to be decoded to 4CIF/D1 analog to allow the matrix to utilize them. Very few (if any) decoders have that capability.