I don't need anything to happen to be optimistic. I already am optimistic for these reasons:

1. They have AR and are always at least in the hunt, so if a few things fall right it can always happen.
2. The big need was CB, and they have opportunities galore to be better: Randall and Rollins to bounce back; King and House to make a difference; Gunther, Hawkins or Waters to progress; one of the presently unknowns to be the next Shields and come out of no where. They don't need all of those thing to happen. They don't need any to happen in a big way. They just need two to happen in a modest way and they will be better. It won't take a lot to be better. They will be better, in part because they have so many opportunities to be better and in part because they can hardly be worse.
3. The new TE group should make a huge difference for the offense. Kendricks alone would have been an improvement. Bennett is a big step beyond that. MM has never had a top receiving TE and top blocking TE at the same time, let alone rolled up in one player like Bennett. To be fair, Kendricks alone might have been a better all around combination TE than MM has ever had, if the evaluations on him are accurate. This should open up the offense perhaps to as good as we have seen under MM.
4. Clark started to come around last year. Lowry (late in the season) and Fackrell (earlier, before injury) each flashed some when given opportunities and healthy. Not predicting great things, but any or all could be pleasant surprises. Again, not looking for pro bowlers, just progression of one or more. Jean Francois will be a steadying influence. Guion will be history.
5. Jones will be given a limited role, but as the season moves on will make a big impact as an almost perfect athlete for the "new" NFL middle linebackers.
6. Nice group of RBs to pick from, at least to start.

Of those things, only Jones is a flat-out guess. All the others are just the natural state of things. Some will happen, some will not. For the most part for the uncertain ones, it doesn't matter which happen and which don't.

I think the team is quite well set up, overall, to be a better team than last year, even if weaker in one or two areas than last year.