I've watched him play since he was 18 and I think I have seen every appearance he has made in the first team. Initially, I thought he had no chance of succeeding as a Premiership striker, because he was exceedingly slow at 18. At that age, it was already plain that the club management didn't agree with my assessment and, as he grew up a bit, it became clear why.
He's still slow, but he's visibly quicker than he was at 18. His big asset is his football brain: he knows where to go and he makes remarkably intelligent runs, on and off the ball, for a striker of his youth. He also passes with vision and brings other attacking players into the game.
I simply disagree with you about his hold-up play - again, you must remember that he's 20 and hold-up play is a skill that develops as a man broadens out physically. Kane may still have some filling-out to do. Today I thought he held up the ball very well, to the point that it was clear that Sherwood had in mind that having two physically strong strikers to whom the ball sticks would compensate for a less-than-hard-tackling 2 man midfield - and it worked.
He doesn't 'miss chances' in the sense of striking the ball wildly or off target. Today all of his shots were on target and that's pretty much typical. But he does shoot too close to the goalkeeper, which is another facet of youth and nerves. He can fix that.
I think that virtuoso run in the second half, beating 4 or 5 Sunderland players on his own, undermines your 'limited skill' claim better than anything I could say. He has very good feet and ball control.
I'm not convinced he will ever be a first choice striker at a top 4 club, basically because of his total lack of pace. But there are quite a few attacking players who have succeeded over the years without speed, by compensating with their intelligence, vision and sense of space. The obvious Spurs example is Teddy Sheringham. Another would be Robbie Keane. Harry Kane has a chance of building that kind of career and the advantage that kind of player has is that he can continue to improve well into his 30s.
From this point, he could turn out pretty good or exceptional - it's too hard to predict, even if you're a professional scout, which neither of us is. But he was more than holding his own against a weak Premiership team today, indeed he was one of our better players.
Robbie Keane was one of the quickest players at Spurs when Jol joined and def was not slow. for a 20 year old i thought Kane looked good and i think there is a lot more to come lets remember he was prolific at youth and some players take time to adjust to the premier league when it comes to scoring. I have seen a lot worse players up front for spurs over the years than Harry Kane he is a good option to have.