Hi Billi,
Will try to answer whtever I am aware of -
1) Can Telepresence integrate with MP Express and be scheduled via that?
ANS - No Clue :(
2) Can Telepresence be used with a Cisco MCU?
ANS - Yes, TP can be used with Cisco MCU but for the integration purpose. Meaning you have other video devices (other than telepresence), and want to have a session between TP and these endpoints then you place a MCU in between. all other devices will be registered to MCU and MCU will talk to Telepresence multipoint switch.
If you question is can MCU act as a replacement of Multipoint Switch for TP endpoints the answer is NO.
3) Can VTA and other 3rd party units (i.e. Tandberg) be part of the same VC that Telepresence takes part in?
ANS - Yes, by using MCU.
heres a good link on the interoperability -
http://www.cisco.com/en/US/docs/telepresence/multipoint_switch/1_1/admin/guide/dh_interop_2.html
HTH
-> Sushil