As far as I know and from my experience, PES determines shots, passes and such from parameters based on the player performing it, not on the ball. The ball most likely has fixed parameters (Basically, there is only one "BALL" in the game) and all variations to shots etc depend on player stats and other factors. In other words, the ball probably doesn't even have a separate mass, instead the game has one fixed physics system designed to work with the object "BALL". So I suppose it would be possible to change ball mass and such if you find a way, but that would mean that all balls are affected equally.
The ultimate goal would be a physics system that is structured like real-life, in other words there are a set of laws that describe how objects will act, and then there are individual and seperate objects that move and are modulated based on the laws. In a situation like that, with optimum settings, you could input weights, structures and distribution of materials to balls, and have them all be affected differently and realistically by the physics laws, instead of programmers having to judge what parameters are needed to make the balls behave realistically.
It is similar to racing simulators, where in the past cars were driven forward by a simple force pushing on them from behind, but in newer and more advanced games, it is the simulated traction from the tires on the road that moves the car. If you simplify it the end result is the same (the car moves forward), but the more advanced system allows for example for different wheels with different treads to provide different tractions during different conditions, and different cambers and other angles provide different behaviours. This could all be done in less technical environments aswell, but then, without the physics laws to help easily keep things realistic, the programmers would have to input parameters based on how they want the car to handle, rather than the physics system automatically and realistically deciding how the car handles based on the physics laws and the characteristics of the object being manipulated.
Another example in PES would be the curl of the ball from the boot. Now, they have a curl value for the player taking the shot, and that value coupled with other factors (balance, stamina) and a general knowledge of what animation is being performed and how the ball hits the boot, the ball gets its curl.
In a better world, the players curl value wouldn't directly affect the curl of the ball, but it would instead dictate how well the player can hit the ball in such a way that the traction of the boot off the ball, and where the on the ball the boot hits it, and with which twist of the foot, etc etc, affect the curl of the ball. In other words, in the more advanced example, you wouyld actually be able to visually see the players foot moving in a way that gives the ball great curl (just as in real life), and a player less adept at curling would actually have different foot movements and strike on the ball, meaning he would get less curl.
Also, in this situation, the ball itself (the material it is made of, how much air is in it, how wet it is) would also affect the curl.
I think this is a bit too much text but...