USA - DWI field tests

[bcubed]

SWIM was recently stopped for an expired registration sticker and made to do three seperate field tests when alcohol was smelled on his breath. After failing two, a portable breathalyser was used and recorded a 0.02% BAC.

What SWIM was wondering: US (technically state, but they're all similar due to federal highway monies being tied in) law makes it such that it behooves one to submit to testing for alcohol in such cases. However, is this in respect to the breathalyser alone or also the "follow my finger" tests, too? I ask because SWIM has taken 5 of these tests (anal college town), never once passed, yet not blown over 0.02 in any case. SWIM doesn't want to give ammunition for "impaired driving" should he ever blow > 0.05 and < 0.08. Is it a violation to sumit only to the breath (or, blood) test? (By this I mean comply with instructions but only make a cursory attempt.)

Also, does the lesser "impaired driving" statute allow field tests to be admissible evidence of driving impairment, or does one actually have to drive poorly at some point?

Finally, SWIM agreed to the breathalyser because he knew that 32oz. of beer over 1hr would not result in a positive test for him. (He did have the officer inform him it wasn't a legally binding test first.) Ought SWIM ALWAYS insist on a blood test in such cases?