In addition to the other answers, new obligations arise under civil litigation disclosure and discovery rules if the family sued for a civil rights violation (assuming that it knows enough to bring a suit that wouldn't automatically be dismissed in the first instance for failure to state a claim).
In this case, it appears that a sufficient lawsuit is pending, so this is really a discovery rule dispute, rather than a question of an independent right to obtain body cam footage outside of the litigation process.
In any criminal action against anyone charged in connection with the incident, not necessarily Taylor, the prosecution has a duty under the U.S. Supreme Court Brady case to disclose any potentially exonerating evidence to the defense, which would usually include all body cam footage. Of course, that only applies if there is someone charged criminally in the incident, which often doesn't happen in police shooting cases.
In this particular case, there was criminal charges brought, but the cases, if I recall correctly, have since been dismissed.
Would any and all statutes for question 2 have to be at the Federal
All or almost all of the statutes would be state statutes. State law differs considerably on this topic and is undergoing considerable legislative revision (in some states to make it harder to access and in some states to make it easier to access) at this time.
Typically, federal law would only apply if federal law enforcement officers were involved in the incident (e.g. a joint federal-state purported drug bust).