About the whole offline GMP/resources getting automatically siphoned into online GMP/resources thing in MGSV. You can apparently stop this from happening altogether by declining the Terms and Conditions that appears at the launch of the game. I think I've had success doing it, but I don't pay close attention to my GMP or resources. Of course, declining the Terms and Conditions forces you to play offline, but you can always agree to the Terms later and go online.
Toparaman's comments