Living in the City of Sonoma
I lived in the city of Sonoma for five years (pre-child) and really enjoyed it. It's true fires have become an issue so you'd want to work with a realtor to consider areas of (relatively) lower risk. Sonoma County is pretty eco-conscious and I can't remember pesticide residues being a concern (someone else may know differently); also many of the vineyards there are farmed organically/sustainably now and overall pesticide use has declined. Be mindful of right-to-farm protections for ag, which in a nutshell means that you can't move to an agricultural area and complain about noise from tractors, smell from manure applications, etc., though those things won't impact you if you live in a town.
Sonoma, Santa Rosa, Petaluma, Sebastopol, Healdsburg are all great towns. Santa Rosa has more services and less "character" than the smaller towns but is livable and friendly. The area around Montgomery Village is especially nice. There are lots of outdoor opportunities all over the county, varied terrain, great produce, friendly people, warm summer days with balmy evenings. Traffic does get worse every year so your commutes would need to factor in. Good luck!