Any good body shop will have a spreader to push that frame back into place. Yes, they might have you sign a release. As the spreader opens, the break gap will close almost to original. They would weld it and add a patch plate.
The other rust, looks like pictures of the TOE board area? Basically panel rust? Yes, you will have to remove everything forward of the firewall. Should be done anyway to check for other hidden problems. Something caused that and it was not normal driving. Once open you will get a better idea of what you are facing. Cost only time. Take lots of pictures as you take it apart.
Nice car, worth the effort.