editing players' position

maybe a silly question, so excuse me first.

i'm running a dinasty and i've seen that i can edit players' position "on the fly"; beside the size/characteristics matters, does the player get some kind of penalty if, for example, i make a pg out of a sf?

nope

The only "kind of penalty" might be that a SF is not made for a PG spot due to his ratings. It might create some problems to your team...

thanks for the answers

you can use this to make some trades, for example if philly needs a center, and you want to mamke a trade with them and you don't have a center to give, just change a player that you don't need, with high rating enough to a center then just trade.
good luck!