Honestly, i would LOVE if PC and JS did do that trade, or maybe trade for a future first rounder, however, i doubt we get a future since there is no "Superstar" in draft worth it. Like you said, there are 2 things, What we do in FA, and if there is a talent Seattle thinks just pop out from anyone else worthy in their "eyes" they must get that they think won't be in the 2nd round. PC&JS could have easily done it with the James Carpenter pick 2 years ago with the #25 pick, however, no one wanted to trade up, this year, i think the same since there is no "superstar". Therefore, i would "Hope" we do that trade for a future or the 2nd,3rd rounders this year, but i don't think it could happen with low demand possibly.
Now, supposedly there is a lot of Defensive line depth in this years draft, from DT to DE, also CB, WR, and OL. There are some good stop-gap DE/DT this year in FA. I really believe we won't draft a DLinemen until the 2nd or even 3rd round(depending on FA of course), along with WR, maybe even TE, i truly believe we go BPA with athleticism and huge upside, meaning high risk high reward player, since there is depth in all position that we need depth at. Which means we could possibly picking at #25 a player we probably won't have expected, if we don't trade down.
Like James Carpenter, Bruce Irvin(even though kearly kind of had a feeling about him, and honostly, i believe he had all the tools PC wanted in a LEO, and i had a feeling too, just thought we get him in 2nd round), most were like who, and why. I have no doubt this year will be the same, and i think we might go OG/OT, because i believe there are a good amount of future Pro Bowler Offensive linemen in this years draft, i know it is not a need, not even remotely, however, if you think about our schedule and our division...9ers, Rams, Cards, all have good DLines..also Texans, Giants, and Bucs, about 8-9 games are against good dlines. However, people like to say continuity is the key to good Oline play, and i don't deny it, but when there are no true "superstar player" worthy of the 1st pick, but much depth from rounds 1-3, but only so few pro bowl caliber, and i think most are in the oline and wr/te position, i don't doubt we go O-line or WR/TE in first round in this years draft, who, TBD.