The salt does penetrate. At first fluid is drawn to the surface and then reabsorbed and the salt enters with it during reabsorption
Takes a day. Some people let it sit for as much 3 days
This is correct for the salt process. You just need one hour for the process. America’s Test Kitchen and Cooks Illustrated are great for the science of cooking.
https://www.cooksillustrated.com/videos/9-when-to-salt-steaks
Pat drying a steak works ok for searing. Salt and air drying is so much better because you are actually breaking down the muscle which tenderizes the meat while pulling existing surface moisture into the meat. Letting it come to room temperature for 1 hr gives the salt time to work. You don’t get much of a temperature change on the interior. However, it can speed cooking times. Banquet service uses this to their advantage. They will sear and rest for 2 hrs which will get internal to near 70s.
The 8-24hrs salt dry age under refrigeration will just give you more of the same. Once you get beyond 24hrs, you will really start changing flavor and texture. You start getting into curing which can ruin a good steak.