With the exception of the "Monitor Program" (which "was not supposed to be included"), the games included were all developed by Tim and Chris Stamper, co-founders of Rare.
Provided they own their own IP, i don't see how this could be a problem.
1) What exactly do you have to do to use Sinclair ROMs in an emulator, such as acknowledgements etc?"
"Amstrad are happy for emulator writers to include images of our copyrighted code as long as the (c)opyright messages are not altered and we appreciate it if the program/manual includes a note to the effect that "Amstrad have kindly given their permission for the redistribution of their copyrighted material but retain that copyright"."
