I think that we are at least 2-3 years away from being competitive and I'll tell you why.
#1 I think that we made a big mistake by drafting Tannehill. I never liked him, I think he has limited upside and he played very small in big games/ situations. Again, I hope I'm wrong but I think we were much better off trading down for Weeden (who I have always liked better) and picking up another 2nd rounder.
#2 It was a big mistake to trade Marshall (particularly for the compensation). He's still young and when he has a real QB/ offensive coordinator he is a top 8-10 WR in football. He's a dominant player, and I think it was very irresponsible to ship him off, especially since without him our receiving corps might be the worst in the league.
#3 Our offensive backfield is extremely overrated by people on this board. Daniel Thomas has done absolutely nothing to impress anybody, Lamar Miller is a rookie, and Reggie Bush just is not a reliable every down back. He's a great role player fit for a team with a good passing game, but he's only had one pretty good rushing year in his entire career. We'll see what happens this year when he starts seeing a lot more 8 man fronts because defenses no longer have to respect any of our players on the outside, or our passing attack in general.
#4 QB is still a tremendous question mark.
#5 We were among the worst in the league at pass D (especially against tight ends) last year and that will probably continue because we still have no safeties.
#6 I have no idea how our front 7 is going to react to playing in a 4-3. I actually have a lot of faith in Wake, as well as our DT corps (which is very good) but our LB corps outside of Dansby is extremely underwhelming. I don't think Dansby is that great anyway.
So, like I said, I hope I'm wrong, but I don't see a whole lot of short term hope for this team. We have a lot of talent at both defensive and offensive tackle, and Cam Wake is still a beast. That being said, we are "meh" at best almost everywhere else.