I don't think customizable move sets means anything for falco and wolf because toon link and lucina are in the game so clones aren't gone yet (seriously sakurai). As for star fox characters that should be in ssb4 here is what I think:
1) Falco is too popular at this point to remove, but that doesn't mean he should still be a clone. Wolf on the other hand isn't really necessary, however he is not really a clone (yes his specials are similar, but everything else about him played completely different). So my proposal is to keep Falco and give him most of Wolf's A attacks (maybe grabs too) and a mix of their B attacks. Something like Falco's blaster, Wolf's angled dash, Falco's tossed reflector, and idk about up B - something new would be nice.
2) Toss out Wolf for the reasons given above (sorry)
3) Include Krystal. Although I'm not a fan of her, she has been in the newer star fox games and she can fill a needed spot. Beyond needing more female characters, ssb needs characters that wield something beside a sword. Krystal has a staff. Unique.