Yes you can mix a Spektrum pro and regular Spektrum reciever. I have a Pro transmitter and a M11. It controls all my regular Spektrum recievers, but there is a big difference when it comes to the Pro. The Pro is faster.
Mixing servos, the Spektrum works fine. I think that most DSM radios will not have a problem with mixed servos. I have both the Spektrum and Nomadio and they drive mixed servos with ease.
Herolin <---Traded my Airtronics for an Ipad and Laptop...
Soon to be GHETTOPRINCIPAL..