There are two quite different questions here, and it would be best to separate them.
As for jumping ability, I look at it this way: frogs and grasshoppers are remarkable jumpers. Why? Because, relative to their overall body weight, a great deal of their muscle mass is concentrated in their legs. There is probably a nearly exact formula one could arrive at, based on accurate enough measurement of these.
I am at least 6 inches taller than the great Spud Webb, yet he could slam dunk with the best of them, whereas I can barely reach the bottom of the net with my biggest vertical leap (and that's without a basketball in my hands). I'm not suggesting that Spud Webb was part frog. But his leg muscles sure were a lot stronger than mine.
As for shooting "ability," especially if this is measured by field goals per shot, there is of course a very large advantage in being taller than everyone else on the court, as Wilt the Stilt was at the height of his career. He once scored over 100 points in a single game, mostly by standing under the net and dropping the ball in when he managed to catch it. But even I had a better free throw shooting percentage than Wilt. Geeze, even my little sister did. I don't think weight or height have anything to do with shooting ability, if this is measured in any reasonable way. Hand-eye coordination is certainly the key thing, as gatman says, if we think about shooting ability in a pure form.
Unfortunately, as gatman also points out, shooting in the modern professional (and collegiate) form of basketball is never anything like a pure thing. Weight and height both become crucial in the physical game played today, because your scoring average will be miserable if you can't muscle people out of the way and score lots of put backs by out rebounding everybody else. Look what happened to Manute Bol when he first joined the NBA and was a mere beanpole.
Clearly, where field goal averages are concerned, you'll do better if you are tall and hefty, too.
