During WW2, numbers of low numbered rifles were rebolted with current production bolts and proof tested. None failed.
Obviously, not all low numbered rifles failed. There were problems with some, resulting from variation in manufacture. Apparently 1917 was not a good year; more bad ones from that year than any other. Probably related to demand for increased production. There were also rifles which failed early in production, ca 1910. Ammunition may have been the problem. Post WW1, there were some problems with a particular batch of NM ammuntion, which resulted in damaged rifles. Keep in mind that when the Mauser action was transmogrified nto the Springfield, Mauser's excellent breeching system was compromised, and a cartridge case failure in a Springfirld is more likely to do harm than in a '98 Mauser.
Was it heating during heat treating that caused the burnt receivers, or heating prior to forging? Like Mausers of the period, the receivers were carburized mild steel; fairly hard to overheat and burn the steel when it is sealed in the carbon pack.
As mentionned, an unaltered Springfield rifle of any vintage is too valuable as a collector's item to alter. If one has been bubba'd past restoration, it could certainly be used to make up a sprorting rifle, although I would tend to avoid using a low number receiver. Rebarrelling a Springfield is not unlike rebarrelling any other rifle with a coned breech and square threads.
The US were not entirely happy with the rather silly 2 piece firing pin, and did work up one piece systems; these tended to be used on NM and sporting rifles.