The problems with the Pete Carroll Seahawks have always boiled down to offense.
They will be fine on defense, Pete is amazing on that side of the ball and knows what he is doing.
The problem with the offense is somewhat complicated, but I will try to simplify it because I don't like writing walls of text.
Pete wants complete control and say on offense even though it isn't his expertise. So coaches on that side of the ball are always going to be inferior yes men, he doesn't want anyone challenging his "philosophy".
He had 2 black holes in Cable & Bevell, players on offense just in general had no shot at developing.
Alex Collins on the Seahawks is a bum. Alex Collins on the Ravens is a top 5 DVOA runningback.
It isn't bad drafting. it is bad coaching.
Jimmy Graham the most dangerous redzone weapon in football with the Saints, is relegated to inline blocker & decoy for his 1st 2.5 seasons with the team. Not a bad trade, just bad coaching.
The final litmus test was Duane Brown. I watched that dude get worse every game he played. After being very impressed with his 1st game, by the end of the year he looked like just a guy at the position.
In terms of how I would rank the Seahawks problems of the last few years it would be.
1 Bad offensive coaching.
2 Bad early free agency signings.
3 Mediocre drafting.
1 & 2 need to get fixed or it won't matter who you're drafting. They won't develop, and they won't play because they will be stuck behind $$$$$ free agent scrubs like Cary Williams, Luke Joeckel, J'Marcus Webb, & Eddie Lacy.

ukeface:
To simplify it even more though it just boils down to running the football at the end of the day.
Pete can take care of the D, Russ can take care of the passing game, now insert a competent running game and the team will be fine. Despite Pete's foibles as a coach.