Hi,
I'll try to answer your questions. Not sure if you meant it this way, but there's no way the phone will run TF nor can you get many/any maps onto it. I suppose you could export some .jpgs with worldfiles, if the phone supports that. But you won't get downloading maps.
As for connecting the Legend to the GPS, I really have no idea. The USB cable that the garmins use are a standard (mini-B, I think) so you shouldn't need to make one. Or does Garmin make one specifically for that phone?
I'm curious, in any case. Maybe you can clarifiy a bit more what you're trying to do.
Thanks.