It was lack of discipline for the most part. The precision simply was rarely there. Nick was the all-time SEC leading rusher at QB. Kylin would go on to lead the SEC in rushing. Guidry did well at the combine. Farrod was a serviceable TE and Aeris was a very good running back who rushed for 1K in the SEC. Jenkins has done well in the NFL and Daryl Williams and Tyre Phillips will be NFL players as well off the o-line. Joe had a lot to work with but I don't believe he pushed Nick enough to get better as a passer and I think if he had sat people like Guidry some for dropping passes I bet they would have gotten a lot better at catching the ball. I think Joe's "top five" or whatever he called it also limited what we could do on offense because with him you're just using those five guys a majority of the time and I think that year we could have used guys like Nick Gibson more than we did and that would have helped us a team more. At MSU we have to use everything that we've got to succeed. He also should have thrown the ball more to Kylin and Aeris wasn't bad catching the ball either.
So, I guess I would say it was discipline number one, followed by some scheme inflexibility number two, and then yeah I agree about what you said about being able to pass the ball competently and Nick always struggled with that and that was a factor. I think the WR drops were a byproduct of poor discipline for the most part.
The best offenses I've ever seen IMO- Walsh's 49ers, Coryell's Chargers, Vermeil's Rams, and Leach's all have one thing in common- they all focused on getting the ball in the hands of multiple players. Limiting it to just five people just isn't very wise.