Carbonating "Wilds"

i don't usually have my beers carbonated in 2 weeks anyways, so i would i say no. my experience on your two questions.
1) mixed yeasts: if mixed means it has sacc in it and you primed it with corn sugar then it will likely follow the basic priming pattern, however i find it to lag slightly (~1-2 weeks) and I think this has to do with a lower pH in the beer.

2) brett-only: brett is going to eat a lot of sugars up, but doesn't usually work very fast so again i'm going to say no, give it 4-6 weeks more than you usually would.

i've got a saison that i bottled ~6 weeks ago that has brett...haven't even thought of opening one, i doubt their ready.

 

I was surprised I didn't know about this one (I teach a soil ecology class so have some limited familiarity with Fusarium, and, of course, I have some familiarity with beer). So I googled, and found this informative link, in case anyone else wants to geek out about fungal pathogens, beer, and gushers: http://morebeer.com/brewingtechniques/bmg/gudmestad.html

One of the paragraphs near the end mentions a reason or two for gushers that didn't make it to Ryan's list.

 

I used
WLP670 American Farmhouse Blend. After 6 weeks, i added some Jolly Pumpkin dregs.

I'm thinking that there won't be much active saison yeast left, hence the delay in carbonation.