Just about to reply to that, but you've beat me to it.
Regarding Felli he is unplayable in spells behind the striker, although WBA had the better of him (ref didn't help). Sacrificing him for Mirallas is less of a jump than the improvement from Neville to Fellaini as it's his defensive ability that really excels. If Felli moved back there it would greatly improve the stability of the midfield and give us more control over the game until Gibson is fit and we can afford the luxury to play Fellaini further forward. In an ideal world we would clone him and have a team of Fellainis.
To play 442 you need a really great central players as they have to do the work of an extra man otherwise risk being over run, and Fellaini is good enough to do the job. Having a ball playing cb also helps to implement a great 442. Plus Vic and Mirallas would be a handful for any defence, think Heskey and Owen a decade ago for England v Germany.
To keep on topic Neville should focus on his badges. Ideally we would have loaned out Coleman and kept Neville as a back-up RB, but with Coleman staying I don't see the point in keeping Neville on as a player. There's a long list of players I'd rather see in the middle before Nev, although to his credit he wasn't the worst Everton player against Swansea.