[T. O'Heir]

There shouldn't be any use or need for a dial indicator. A dial indicator won't measure the thickness of anything. They're used to check flatness and roundness of machined parts mostly.
There's no need to measure looseness in case gauges or primer depth either. Knowing either really won't tell you anything.
Primers are seated until the ram won't go in anymore. There is no adjusting primer depth.
Case gauges are usually 'Go' or 'No-Go' for checking a tolerance. They don't tell you much that's useful either.
"...Don't get the digital ones..." A digital Vernier is far easier to read. They are not easier to make errors using either. A square only tells you if something is square.