probably, almost definitely, overcarbed...

I made a brewer's best witbier kit as my first attempt, fermented between 61-64, tasted great going into bottles.

Mixed up the priming sugar from the kit, bottled, capped, and it's resting in a dark 72 degree closet right now with a little more than a week before I can try one.

Just realized this morning that my final volume was around 4 gallons (rookie mistakes, didn't filter out spices when transferring to primary, so my siphon kept getting clogged and introducing more oxygen), and I still used the fill 5oz of sugar... Combine that with fact that the calculators I've found say that witbier tends to need not as much carbing as others (2.3 to 2.7 volumes is one I found, which equals about 3.5 ounces on a 4 gallon bagch.) and i'm afraid I've screwed the pooch on my first batch... Is there anything I can do at this point, or just ride it out? How piss poor is it going to be if it's that far overcarbed, and am I in danger of exploding sometime soon?

one time i only bottled half a batch -- 2.5 gallons -- and added all the priming sugar as i would have for a five gallon batch. it worked out to almost 4.5 volumes. i was worried, but it was fine. very bubbly, but no bottle bombs or anything. i was sure to put the bottles in the fridge for 24 hours before opening.

Using this calc and plugging in you get 5 ish ounces for 4 gal at 3.1-2 vol. According to this you should be fine, but just be careful. I've never carbed this high but it could be fine. No promises though.

http://www.northernbrewer.com/priming-sugar-calculator/

Traditionally, German wheats, especially Hefeweizens, are carbed up in the high 3's/low 4's CO2 atmospheres. I think you'll be OK on the carb front.

As far as bottle bombs, typical beer bottles are only rated to 4.0 atmospheres of pressure. I've found that most can definitely take a little more than that, but you will start getting bottle bombs around 4.0 for bottles with imperfections. I have a Hefe bottle carbing right now that I carbed to just under 4.0 atmospheres, and it should be almost perfect with no bottle bombs so far after a week.

You are in good shape!

Hmm. I guess that's good to know. Some calculators I saw have Witbier listed at the lower, 2.3-2.7 range. I'm glad I (probably) won't explode some bottles, just hope the beer doesn't suck.