I don't think most safety's in the league respect Nichols arm enough to beat them vertically or with long outs. If the Bombers are able to isolate someone and get the safety to bite down enough then Nichols is fine throwing a deep ball. I don't know whether it's a LaPolice thing to be honest, it's not like all of the routes are underneath or backfield outlet options, seems to me they always have guys going upfield, Nichols just rarely makes that read, he doesn't attack enough. It just strikes me that he doesn't keep secondary's on their back foot by being able to fire some lasers over the top, which I think is a function of his overall arm strength. Maybe he's just really crappy at looking the safety off, it's hard to tell on TV and I don't get to many games live. Regardless something is up, defenses are just stacking the box and taking away the underneath plays over the middle.
I agree with you that his decision making is iffy when the opportunity presents itself and wholeheartedly agree that they abandon Harris far too often along the ground early. He's the key for Nichols, it's not rocket science, Harris makes defenses hesitate, they have to respect his getting the ball so they can't simply pin their ears back or sit back and let him get 6-7 yards before they touch him.