Yea, I mean I posted some long thing a month or so ago saying we can build for the future with a QB at 4 while also shooting for a Super Bowl now by mortgaging the future to an extent in free agency with a window of trying to win in the next 2-3 years. I mentioned Denver as the example, when they signed Ware, Talib and Ward to big deals to go along with young pieces like Miller, Harris, Jackson, Wolfe, etc.
We have some young pieces in Lawrence, Crawford, Jones, maybe Gregory, on top of Lee/Scandrick, if we go out and aggressively pursue 2-3 guys who could start on defense, many of which you named, we could certainly have a defense worthy of a title with a healthy offense. Our defense doesn't need to be Denver's because our offense will be better.
I also don't think Trevathan will break the bank, he will cost, probably about 7-8 a year, but I don't see the guy getting a Kuechly or even Wagner deal. He's probably a pipe dream either way, but guys like Zach Brown and Demario Davis need to be targets.