Agreed, way more efficient to use your teeth

Amazingly, of the 14 vaccines routinely administered to babies today 8 of them were developed through the work of little known Maurice Hilleman and his team

You probably could do any old street mouse but there are companies who produce litter after litter of genetic cloned mice so that your results are consistent and not dependent upon genetic variation. There are different mouse models, but in many cases the mice have compromised or differently engineered immune systems to mitigate immune system interference.

Typical experiments use mouse cancer cell lines so if injected into a human it would be rejected by your immune system, but there are some models of mice with humanized immune systems which are capable of acquiring human cell tumors and those cells could theoretically be transplanted into people. Usually no hazmat suits AFAIK, just typical gloves and lab coat. I am merely a synthetic organic chemist so I don't know much more detail beyond that but have learned enough about it through colleagues who go on to test the things we make

I think it depends on who you ask, but most likely the people engaging in this work would believe that it is necessary at the moment to move medicine forward. There are panels that oversee the experimental design of any such study and I can assure you that they take their job very seriously. My PI in grad school was roasted by them during a meeting because he had not adequately outlined a pain management protocol for the mice in our study that were getting an experimental cancer drug. Everything in these studies is done with ethics at heart

Cancer cells are grown in vitro and then injected into the animal at the desired location of the tumor. For most reliable model systems the parameters for what cell subtype to use and how many cells to inject are known and published

Carbon assumes a hybridized valence structure in molecular orbital theory where it forms four bonds, not the two you would assume from its atomic orbital structure. In the case of graphene those carbons are sp2 hybridized so it makes 4 bonds to 3 other carbons.

South of Asheville is still pretty green but starting to turn so could be in luck!