This raise can change the position of my SF and turn it to a PF on the future.
Maybe you are giving too much importance to the position in upper right corner of your player. This position is assigned by game engine (GE) and is important for new players so they know where to put such players when setting their lineup. It doesn't mean his salary will be greater if he is a PF rather than SF or that he will train slower in outside skills if he's not a SF. You can totally ignore what he turns into. If you take a C and train him enough in Passing and Outside defense, he will inevitably become a Point Guard. Does that mean he's a Point guard now? No, it just means he's a C who can pass and defend outside shots well, but GE still assigns a "PG" to his position.
Are you sure that 1 level more of IS it's the same price on a SF or PF??
then you shouldn't train IS, when you like to keep him SF ;)
That's the point, i'll have to stop training inside skills if it changes to PF position just because 1 unexpected level of SB.
not really ;)
The secondary SB training makes you around 50$ difference in salary so you 75.500$ SF will be if it switch a 75.599$ PF. If you train both players one weak in IS you probadly get a 76.500$ PF or a 76.549$ PF. So the difference would be still the same, and really really small so if those 50 bucks will kill, i like to see your data to approave it.(yes both salary increase are calculated very high)
Second point is, when those training wasn't reduced from the main skill, and go to the relativ low SB skill the salry would be even higher - so you should praise the BB that they avoid your bancrupcy even longer even when you are still 50$ over your payroll.