Is it safe to dismiss a positive ana speckled with a titer of 1:640 if cbc ok. lupus panel negative. metabolic ok. urine ok. serum protein ok?

Yes and no: We have a saying in pathology / lab medicine, "treat the person, not the labs." plenty of healthy folks have medium-titer speckled ana's. The real question is, "do we want to treat you for lupus or whatever, with all the unpleasantness that this involves?" i think the answer is "no" based on what you're shared if your physician agrees. Remember the ANA should new symptoms develop. Good question.