Yeah, I have had issues with Voyager letting me upload pics as well, though the message I get is something along the lines of "this application doesn't allow picture modification here."
I still have Sync installed so I can upload images.
I don't think so? I think Voyager just doesn't like having images in text replies. I could, for instance, write this comment in Voyager, open the comment in Sync and add in the picture if I want.