* it is normal to judge wine and see a fraction with bubbles on a glass. Home wine is not squeaky clean.
* yes CO2 will travel through the airlock. The gas law is solubility is a function of the partial pressure on the atmosphere above the wine. This means if you were squeaky clean / no CO2 some would dissolve back into the wine via dissolving in the airlock water.
* I degas three days to a week before bottling. CO2 helps with protect the wine as long as it outgasses.
* the solubility of CO2 is higher cold. Degassing works better if the carboy is warm. ,,, Practically speaking serving temp is all one has to plan on, ,, folks don’t microwave their glass of wine to see if CO2 boils off. (Well at least normal folks).
* if it doesn’t taste like seltzer / off, it doesn’t matter.