But you haven't watched all the others you have in your stats. Those variables you mention are a very small percentage of everything that should be considered. It's pretty much impossible to accurately prove anything from these kind of stats.
Does a shot from inside the area mean it's a better chance than outside? Not necessarily. For example, a shot an inch from the box vs one two inches further ahead inside the area, no difference. What about defenders standing in the way? Surely a chance from outside the box is better with no one in the way vs one closer to goal with 2-3 defenders standing infront. Then there's the question of what is the level of the defense you're playing against, the GK. Time afforded, angle, height, curve and speed of the cross coming toward you. Seriously, I could go on all day and still find more factors that should be taken into consideration. Some of these things are impossible to judge. An example being the header he had against Liverpool that people labeled as a sitter.
You could estimate how good a chance is, which is what these stat sites do, but it is to subjective to really be established as a definitive conclusion as true.
Having said all this, I do agree he isn't clinical. But he get's himself in good postions to create chances, thus taking more shots. I can't say anything about the others since I havent watched them much. But I do think some are trying to make out Zlatans chances as better than they actually are.
A player that panics in the box only to take difficult shots?
Does Ronaldo do that too, since the shots he takes aren't always easy? Real Madrid must have a really big problem there.
Actually, I shouldn't be laughing since some of the bicycle kicks, volleys and kung fu shots really are difficult to score from. But I wouldn't say he panics, just that he tends to take more difficult shots at times.