I think your post needs to be framed by the opinion that Vaz is the presumptive catcher from now until the foreseeable future, with Swihart at best getting 33% or so of the catching load. Because IMO Swihart still has a chance to be an elite player as a full-time catcher.
You may be right in terms of the Red Sox plans, but I'm not sure it's the best plan. For one, Vaz's bat is a pretty large negative. Yes, on b-ref, where they bake positional adjustment into both oWAR and dWAR his offense doesn't look *that* bad. But, among catchers with regular playing time, he has the worst OPS, worst wOBA, and second worst FG oWAR (Yan Gomes has similar rate but in more PA).
Now, he shouldn't be as bad as he has been. But I'm also worried that his defense has been overrated, largely because I don't see much of a case for anyone that has pitched as a Red Sox with him catching being improved compared to throwing to other catchers on the Red Sox, or other teams. Of course these effects are hard to see because the individual samples are small. But, the Red Sox have not been a good pitching team with Christian Vazquez catching. While it's not his *fault* per se, and you can still make the argument that they would be worse without him, I'm not seeing a lot of evidence that his outrageous defensive projections have any merit.
All of that said, if the Sox consider Vazquez to be Yadier Molina and consider Swihart to be more Jim Leyritz than Jason Varitek then yes, Swihart should be on the trade block - as soon as he's healthy, which may not be soon enough to help the 2016 Red Sox.