As others have mentioned, Mata, Rashford and Martial would all be better signings for us than Rooney at this stage in time if we're buying from United
The big reason to sign Rooney is that it'd be a world recognised player whose name we could put on shirts and make some decent money, but he's not the sort of player we need starting for us every week
He's not coming to Everton to sit on a bench for less money than he's on right now
If he wants to go to Russia in 2018 as an England player, then he's going to have to play regularly, and do we want him playing regularly in place of the likes of Lukaku, Barkley, Lookman, Davies etc?
Great though it would be to see him wear the shirt again, he's probably going to want more money and minutes than we're prepared to offer him
If he's willing to take a substantial cut in his wages and be back up for Rom, then I'd happily have him here. If he wants a decent wedge and to be in the starting XI, then I'd have to seriously question that deal