~1yr black mold exposure unaware. Sinus symptoms 3 mo. Now had acute exposure; can nasal irrigation push spores deeper&risk dangerous fung infx? Or good2do?

Should be fine. Most sinus/respiratory symptoms related to mold exposure are due to an allergic type reaction as well as irritating toxins. Using irrigation to clear out the spores would help with both of these problems. Serious "invasive" fungal infections of the sinuses are rare and occur in people who have uncontrolled diabetes or severely suppressed immune systems. "Black mold" does not cause these infections.