Has he violated your 4th amendment rights by seizing you even if you didn’t fail the sobriety test?

You do have a point, since it is not having had something to drink that is the crux of the crime but being under the influence.

You may have a cause of action under 42 USC 1983.

Yes and no. He doesn't need to have formed a suspicion to use the PAS. They say that's one of the tools to determine intoxication, but if you passed all tests he doesn't have probable cause to arrest you.

You need to hire a DUI specialist, and do it soon because you have only 10 days to save your license. Whether you failed the FSTs or not is a matter of perspective (FYI nobody ever passes, because they are designed for you to fail).

The officer needs probable cause to place you under arrest for DUI. While the field sobriety tests can give them probable cause, you can still be placed under arrest if the officer can point to other factors giving probable cause. For example, a strong odor of alcohol, admitting to drinking, slurred speech. This is where you need an experienced DUI attorney to carefully review the stop and administering the field sobriety test, to determine if the officer had probable cause. There may be issues with the calibration or maintenance of the breath test that could get the charges reduced or dismissed.

Probable cause determinations are made on the totality of the circumstances, which cannot be gleaned from a four sentence post. Even if a court determines there was no probable cause for the arrest, police have good faith immunity from civil suit. If a court finds probable cause for the arrest, you will not have a civil suit even if you are not convicted. You should be seeking counsel to defend the drunk driving case first, and worry about?the unlikely possibility of a civil suit later.