Keep the "Discover debt: $2300 at ZERO% until 1/14". Ideally move VISA card "A" and "B" to the Chase Slate offer 0% w/1% fee. If you can't move all of it, move as much as you can, since the 1% fee is the best out of the lot. What you can't move onto the Chase, put the rest on the Discover 0% w/3% fee.
So hopefully you will end up with:
Discover debt: $2300 at ZERO% until 1/14
Chase Slate offer: 5250+7125 = 12375 0% until 3/14
You only gave what your minimum payment was on two of them, so if taken together let's say your new minimum is 270, and on the discover we'll guess 100.
Since you have 0% now on all of them, you won't actually be reducing any compounded interest you pay, so it doesn't matter what the extra money goes to. BUT, since the discover 0% will be over first, plus it's the lower of the amounts, put your extra money towards that. If you're averaging about $200 extra, plus the guess of 100 for the min payment, that's $300/month towards it. $2300/$300 = 7.6 months. We'll say 8 months, so doing this will eliminate that one in 12/13, a month before your 0% will run out. Now all you have is what's left on the other one.
With your min payments, that one is down to $10215 in 12/13. Since the other one is paid off though, now instead of your min payment of 270, you can add in the 300 on the other one and pay $570/month to knock it down more quickly. That only knocks it down to 8505 by the time that 0% runs out, so you will want to transfer it again and keep on paying the 570/month on it. Hopefully you can find another 0%/yr, because in 15 months paying 570/month that one will disappear too.
So less than 2 years and you can be free of it. Hopefully less if you can push more than than your avg 200/month extra at it.