The answer to whether you can do this without a lawyer depends on your legal knowledge and litigation skills. You have the right to represent yourself - but do you have the skill? Your questions go to probable cause for the stop and admissibility of the breathalyzer which are complex legal issues. The answers would depend on the evidence that would come out if the issues are brought to hearing and the legal arguments made about the facts.
Please understand that answering this doesn't create an attorney/client relationship between us, and as hard as I try to answer your question well, it isn't legal advice. No matter how much information you put into a question, the answers you are going to get are still going to be vague. It is in your interest to contact a lawyer, most of whom will do a free consultation. Even 15 minutes with a lawyer is going to produce a more specific answer to your problem.
A DUI is a serious charge and can have some pretty severe consequences. On top of that, the court system is complicated. Most people who try to defend themselves end up getting lost in it. If you think you have a good legal issue you still need to know how to draft a motion, how, when and where to file it, and how to argue it. You may quickly find yourself out matched by the State's prosecutor.
As far as a dismissal goes I would say it would be difficult. Even with a good legal issue judges are hesitant to dismiss cases. If there is any way that your case can make it past the motion phase and on to a jury, the judge will usually go that way. They usually err on the side of letting a jury hear your case.
Hire a lawyer. Even if you want to do this yourself you are going to need someone's legal advice to help you through the system
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