Everyone agrees that Marvel can be successful with lower tier characters given the right director, script, and creative team yet, hardly anyone applies this concept to Fox's Marvel properties. Granted I agree to an extent that some of there movies did suck it wasn't all their fault. XM
OFP could be a really great XM film given the amazing storyline, the bringing back of the director who made the first two XM films who everyone agrees were great so while Singer may not have a great track record with everything else he does have one with X films.
And as far as a FF reboot I have faith that Trank can do it justice. Give him the right creative team and script with Millar helping out he could do wonders.
As for a SS movie I don't know much about the character save from his FF ties if given the right things it could work.