IMD: it's best to leave it alone now. When they first introduced it around 1.05, I think they didn't account for its impact gameplay-wise. Now that the game has been 'tuned around it', I've seen no need to change it off of how it appears in-game.
QBA: It's relative to the settings, but when using an all-default All Pro setup, my observations have been that lowering either one dumbs-down the gameplay. Coverage gets looser on both sides, CPU QBs get dumber....it just makes All Pro a watered-down experience without extensive slider modifications. I've not tested QBA on All Madden so I will not speak to that. Frankly speaking, there is no need to adjust these on All Pro, the ratings will very much drive the accuracy of the throws.