If Cylon's jump technology is based on wormholes, I would suppose, their FTL radio would be based on a similar tecnology. I don't see why you can't argue their downloading is based on some form of microscopic wormhole technology. Baltar and Caprica 6's "psychological melding" was a leap of creative effort that RDM has prefered to leave unexplained. Again, an argument could be made that "Head Baltar" and "Head 6" are side effects of their close proximity, Caprica 6's uploading, and Baltars terror during the nuclear explosion and blastwave that hit Baltar's home. If they're a little tangled up on the wormhole front it might explain why Baltar's and Caprica 6' personalities can talk to each other. I'm not saying this is how it is but it does help knock some of the different problems into a coherent and simple whole.