I agree with the other posters; it's not possible. I just wanted to point out that a pardon, even if you can get it, won't expunge or erase the DUI from your record. It just attaches a statement from the State of GA saying that they've pardoned the crime.
There's always a chance of early termination, and it definitely helps if your PO is on board with it. Of course, it will depend entirely on the facts of your case, including any mitigating factors (if you have children, work multiple jobs, need to get off probation to begin some new position, etc. Forsyth county can be a tough place for a DUI defendant, but I've found that they're generally reasonable if you're taking responsibility and doing what you're supposed to.
As for who's the best...
Depending on your budget, you should be able to find someone to represent you. Fees are a difficult thing; you want to find someone within your budget, but you want that person to be able to invest as much time in your case as possible. Many of us are flexible and can offer payment plans, so don't give up!
That's definitely a good way to attack the credibility of the officer. Every case is different, but depending on the facts of your case and your own history (or lack of any criminal history), you may be able to get your charges reduced. Unfortunately, many prosecutors won't reduce your case unless you have good representation to argue on your behalf. It's always risky to handle a matter like this on your own, since your statements can be used against you, so call around and find an attorney...
It sounds like you have a pretty strong case, especially since you had a head injury. It's hard for you to perform flawlessly on the field sobriety evaluations with a head injury. You'll need a good DUI attorney to argue on your behalf, though, as the prosecutor is unlikely to reduce or dismiss your case without counsel. It would be very hard for them to prove guilt beyond a reasonable doubt at trial without a blood or breath test.
You should raise your concerns with your lawyer. Give him or her a chance to respond to your concerns, and that may solve any issues. I'm always surprised when people don't raise their concerns with their lawyer first. If you're still not satisfied after that, you have the right to choose another lawyer, but you may end up with the same result.
I'd agree with the other answers here; you need to act quickly to protect your driving privileges, and a good DUI attorney can help to maximize your chances of getting the charges reduced to a non DUI disposition. Call around and find someone you're comfortable with at a reasonable price for their services.
If you're talking about the breath test prior to arrest, that is different from the official breath test that would have been administered later, at the station. That portable breath test at the scene is very unreliable, and it does spit out a numerical result, though the officer isn't required to show that to you. As for the field sobriety tests, if you're given confusing instructions, it's impossible for you to perform those evaluations correctly. You definitely need to speak with a DUI...
The warrant will remain valid until it is cleared by either withdrawal or by arrest (booking into jail). This will really depend on where the case is--some courts will allow you to post some money as a bond and then put the case back on the calendar. But the warrant will certainly not expire on its own after a certain amount of time. Feel free to call any time to discuss in more detail at no charge. 404-987-0245