The only Verizon data limitation that comes to mind is using cellular data, where you get 2GB on a regular data plan. If you've already uploaded the pictures to your phone, you've already incurred the cellular data charges (assuming that you didn't use WiFi) to upload the pictures. There's no cost that I'm aware of just to have photos on your phone...On the other hand, if you uploaded the pictures via WiFi, then there are no charges at all, since Verizon doesn't charge for data transfer via WiFi.
Can you please be more specific about what Verizon data limitations you're speaking of? I'm sure that there's a way to remove the pictures (good idea to turn off syncing pictures before removing them, though *smile*, you can do that in your settings under your Google account), but I don't know what data charges you're worried about?
Thanks, sorry if I'm just dense here...