Full disclosure, I'm an MSU grad, but I think you're focused to much on info people are using to justify ranking us last in the west and not digging very deep.
We return the second most snaps in the SEC on defense, so the # of returning starters is a little deceiving. Chris Jones, Nate James, and AJ Jefferson are all likely NFL draft picks next year from the DL, although we won't be as deep. The LB's will be better in coverage but not the run stoppers they were last year. Will Redmond was listed as the #1 senior CB this year and Taveze Calhoun, also a senior, is not far behind him. Deontay Evans will start at safety and is also a senior so your comment about our secondary being young is just plain incorrect. We are young after these 3, but our scheme was so bad last year I expect that alone to improve our pass defense.
As for losing Josh Robinson, RBs are easy to replace. His weakness of being easy to tackle low was exposed late in the year and was part of the reason we lost late in the season. I don't expect much if any drop off this year as Dontavian Lee was a much more highly recruited player and should win the starting job early in the season.
It's also nice to return the best QB in the SEC and most of our production at WR. Jameon Lewis was out the second half of the season and Johnson started because he was a senior but was probably our 4th best WR. Dak played with a broken bone in his foot the last 6 games of the season, so if he stays healthy he will be even more dangerous as a runner.
I am concerned about our OL, but it's not like any of the departures got drafted. All reports from the spring are positive, but I understand the source is biased.
I know this is focused on positives, but since you only focused on negatives i felt this was the proper yin to your yang.
All of that said, I don't think there will be much difference between 1st and last in the SEC west. Any team could win and only Alabama would shock me in last.
I would be carful with the A&M pick you have. Check the stats half way through the 4th quarter when the game was in hand and they will tell a very different story than you are.