i'm no pro but here goes: while it won't make bar beer good, it sounds like there's quite a bit of residual sugar left since you're FG wasn't what you expected it to be. this means the brett will have something to munch on and you can definitely expect a much different taste in 6mos-year. in the book wild brews there's a chart that shows when the real souring happens (acetorbacteria v. lactobacillus & pedioccuss (sp?))so expect to have to wait a year minimum for any real "souring". i say pitch some funk, and perhaps toss some in some extra sugars for fuel for the buggies.
if you won't miss the beer give it a shot, what's the worst that can happen? just try not to aerate the beer too much when you pour all the bottles back into whatever vessel you're using, oxidation can cause to much acetobacteria & cause vinegar.
if the beer is too high alcohol you're SOL. as previously stated the bugs do not like high alcohol conditions...