I guess having your windows open all the time can also have it's drawbacks. Last night there was a skunk nearby. It was close enough to my house to "buttercup" me through my c-pap machine.
You can in San Diego. Here in CT, I run a blower into my basement fish room controlled by my apex. As long as the outside temperature is between 60 and 75 it runs. That actually helps with pH, whereas a skimmer line does not.
Depends. Certainly don’t do silly things like adding chemicals, particularly if your low stays above 7.6, but sensible things to help to drive down unnaturally high CO2 levels are well worthwhile.