Not sure if the F-15C had any SFM changes made from FC2 to FC3. However they are making an advanced flight model for it, but there isn't a whole lot of details on performance differences yet.
I don't fly with AI wingmen so I don't know if anything has changed.
Nevada is on the way as an official terrain that will probably cost at least a little. It was a pre-order bonus for the A-10C, and they have said that they want to honor that. So if you pre-ordered A-10C you should get Nevada.
