You have gotten some great answers to your questions so far. One point I wanted to make is concerning your not being able to determine if you have clarity across the photo. If you are shooting landscapes, focusing on the hyperfocal point can remove that concern. I use this method all the time and never worry about what is in focus because I know the focal range before I shoot. Are you using the hyperfocal distance at all?
Jerry Jaynes Great Smoky Mountains of North Carolina