I think Donald solidified himself as a Top 20 pick, with the way he was dominated alleged 2nd round prospects like Cyril RIchardson in practice and then Gabe Jackson in the game. The comparisons between him and Geno Atkins/Jurrell Casey were out there and sporadic at the end of the season, but now they have completely gone off the rails since then. Unless he has a really bad combine, you can't put the genie back in the bottle and thus he'll almost certainly be one of the Top 32 players selected, and potentially the first DT off the board since the need at the position in the middle part of the round (CHI at 14 and DAL at 17) include teams that are perfect fits for his disruptive 3-technique role.
I don't see the Falcons trading back really. It's still early in the process, but who/what are teams going to be trading up for. Basically the options are Clowney or a QB. And I think when the process is over, the QBs won't be as highly regarded as they were a few weeks ago. I don't think NFL people are going to love Bortles as much as some in the media are portraying him to be, and I think he's the Ryan Tannehill of this class. Derek Carr has all the signs of Christian Ponder v2.0, and I believe NFL teams learned their lesson last year when they didn't reach on lesser valued QBs like him in Round 1. If Carr goes in the 1st, I believe it will come at the end of the round where a team trades back in. Or maybe a team like JAX or OAK trades out of the Top 5 with a team looking to draft Clowney and into the middle range (again CHI or DAL jump to mind) and then take Carr there.
Trading back is always an option but probably not that realistic.
Matthews/Mack, those are the guys you might want to start getting familiar with at this point, because they have all the hallmarks of being Falcons picks: seniors, captains, several years of production, fill needs, etc.
"Vincere scis, Hannibal, victoria uti nescis" -- Maharbal, 216 B.C.E.