My core switch is a 6513, distribution is 3750E, most edge switches are 2960 or 3560 series. A few (example 2960-8-TS) only support 64 Vlans, and our VoIP Vlans and others don't make it to the dumber switch. I have to manually set up the smal (and dumb)l switch without VTP. Will VTP pruning allow me to get the 64 Vlan edge switch to interoperate as a VTP client with the big domain?
The VTP Pruning feature will not help you, unfortunately. The goal of VTP Pruning is to temporarily block existing unused VLANs on trunks to prevent broadcasts from unnecessarily flooding into parts of network where there is no member of those VLANs. However, the VLANs will not be removed from the VLAN database, but rather only selectively blocked or unblocked on trunk ports. The size of the VLAN database will not be smaller.
Probably the only feasible course of action for you is to move the switch into the VTP Transparent mode as you originally suggested.
Please note that even if a switch does not have any access ports in a VLAN, it must know about those VLANs which are traversing it via trunks. If a frame tagged with VLAN X enters a switch via a trunk, and the VLAN X is not defined on that switch, the frame will be dropped rather than forwarded out some other trunk. Bear this in mind when minimizing the number of VLANs on your switch.