jennyema
Chef Extraordinaire
ALL SALTS are around 99% sodium chloride and have the same saltiness per unit of weight, though not by measure volume because of grain size.
Yes. It's important to remember that all salt is essentially the same, and is equally salty.
The difference in salts is found in the size of the grain and the addition of iodine in table salt and the naturally occurring minerals and other "sea stuff" in sea salt.
You can certainly bake and cook with sea salt.
Personally I never do because sea salt is relatively expensive and there's no benefit in using it. The subtle taste differences in sea salt are lost when you bake with it or use it in a cooked dish. I use it almost exclusively as a finishing salt. I do have a table shaker of sea salt that someone gave me, so I use that but won't replace it.
Otherwise it's kosher salt for pretty much everything.