Thank you for the kind words--always appreciate another group that truly wants the best stab at realism (as opposed to what I find a lot of folks want, which is their version of what realism should feel like). Obviously it'll never be perfect, but offense should be difficult.
I initially did use the net passing yardage using the formula you listed second as a way to measure/balance the aggression trade-off vs the NFL. In theory, I thought, net passing should even out, but how guys achieved that (going deep with more incompletions/sacks vs safer with more completions & fewer sacks) could differ. I've done a lot of reading up on NFL research/studies since embarking on this stat/slider journey, and part of what I read mirrored what I found: that the more aggressively teams start passing, the higher their yards/att AND net yards/att tend to get (NFL study). That doesn't mean the offense improved necessarily--but this metric would rise. It didn't "even out," in other words. My theory on why this occurs is just the nature of offense & defense: in a given drive, to move the ball, the offense has to keep succeeding whereas the defense only has to succeed once, as it were. You could have higher net yards/att by throwing deeper, but that doesn't actually necessarily mean you're consistently converting 3rd downs any more often than a more conservative offense. For every 1st down you get that a safer offense may not, you probably also have more 2nd/3rd & longs that lead to punts. This was part of why I stopped looking for a single, aggregate passing success metric to balance against and instead accepted that I would need to look at the pieces that make up the whole: 'simple' yds/att, completion %, sack rate, int rate, yds through the air vs YAC, etc.
Most guys in our league are incredibly aggressive, by NFL standards. Half of them don't even realize they are, but Madden has trained us to look 15-20 yds down the middle of the field and if the pressure is coming, hey, give the throw a try anyway! This is, of course, in many ways the very definition of poor QB decision-making in the NFL. So our INTs are sky-high, but so is our yds through the air & yds per attempt. From everything I see, the primary reason our scoring is higher than the NFL is because we turn the ball over more, which gives offenses more short-field opportunities. Our 3rd down conversion % is *identical* to the NFL (39%), our rushing is in a very good place vs the NFL, our completion rate is lower, etc. Even just watching games with the eye test, a lot of our scoring is off takeaways. Much more than the NFL, because again, our players don't take care of the ball.
You understand what most do not--you can balance to force the stats you want, which can lead to unrealistic gameplay--or you can balance for the best version of an NFL-like risk/reward trade-off in gameplay and let the stats fall where they may, to a degree. I choose the latter. We do have 1-2 teams who are skilled enough & have the personnel to make a hyper-aggressive passing attack work. But one missed the playoffs & the other lost in the AFC Conf Championship on the back of 6 INTs when he finally faced a top-tier defense who knew what was coming. Everyone else who plays this way has some big games & some downright awful/ugly games. Most of our consistently best/balanced teams take care of the ball, generally don't force it, and throw at or even slightly below NFL-average INT rates. This is not an accident, and it reinforces my belief that these otherwise kinda brutal sliders reward playing like an NFL QB would play.
That's NOT to say you can't take shots aggressively--none of the top teams are strictly dink & dunkers--but they/we pick our spots, we only go deep when it's there, we try our best not to force it, we take the 3-5 yd plays if that's what is there & put together drives. And when we do go deep it's not 20 yds down the middle of the field into the heart of 2-3 adjacent zones.