New Role

[RaiKo]

All have the same kind of answer really, as every players performance will depend on how the contributive roles are assigned among your team.
so,
1- testing him, you should notice the differance and the differance of other players too, maybe you have a better player, as a DR candidate and this guy scores positioned as MR... thats all internal, a contribution then, in attack terms, can be in goals or assists... so... "depend" ...
2- as said, test, and you'll notice, because its so perceptible. Play a normal friendly vs a 1* team.to oversize the internal programming. a Key Player will probably score like 3+ goals per match there and you'll be able to know which players appear, contribute and which, simply do not in just a couple of games.
3-same as above, depend of the "engine desires", we control 0 really, if a player, is probgrammed, to score 3 goals as ST even with 9* and another, with 5* is programmed to score 40 goals in a season, as I experienced with the potato scout I bought 90 seasons ago and that I called Cissé... who scored the "3" ...lol then you learn how this game proceeds and that you can't create intentionally a CR7, but the game have to allow you by setting predetermined parameters.

Thank you Khris for detailed answer. What I understand is player's first role doesn't mean they are programmed to perform best on it. However, assigned roles, player skills and performance working separately.

e.g. Single DR player may perform his best on AMR position(actually he was programmed to AMR in hidden) if you add it on him later. To find it, we need to test in different positions and circumstances which is very hard and complicated imo. It would be good to hear player's first role is his dedicated and programmed position. e.g. DR/MR/AMR player performance coefficient is multiplied by 100% as DR, 80% as MR and 60% when he plays in AMR.