I don't believe you can use the badges past this particular promo, so I'd definitely use them up.
I used my badges but now MF is tomorrow. I was under the impression that MF was not the same as FoF. So is MF a mini promo within FoF or a separate thing and if separate will that make all these FoF cards I saved up useless?
That's what I wanna know.
It's within the promo, FoF players will be used just like the past promos. The only difference is that this is the "main event" promo, and will likely have more to it than the previous two.