He's 18, 5-6 years means he's looking at a starting role at 24? He's been with us from a young age and he'll be desperate to make it here. You need 4 top strikers, as we've seen Rooney's form is patchy and Hernandez needs creativity to get the best out of him (i.e. to spot his runs behind), Welbeck is yet to show he can consistently score at this level (although I have no doubts he will). 4 strikers, top ones at that allows you rotate and cover for injuries and loss of form, it's not a problem at all.
Confidence doesn't equate to certainty, it means more likely than not. He's a very special player Keane and the situation is different, if anything Rossi not making it here would mean SAF will be more patient with Keane. Apparently a host of Championship clubs are after him on loan and he's already capped for the U-21's so it's harsh and wrong IMO for you to say Rossi was a far greater talent. Keane's a different type of forward anyway.