Facebook trained the model on an Internet's worth of copyrighted material without any regard for licenses whatsoever - even if model weights are copyrightable, which is an open question, you're doing the exact same thing they did. Probably not a bulletproof legal defense though.
Yes, and there have already been court cases that ruled AI training of copyrighted data to be fair use, because it's technically no different than any other form of art, everything is based off of seeing other ideas elsewhere, there are no new ideas anymore.
https://huggingface.co/meta-llama/Llama-3.1-70B-Instruct/blo...