welcome aboard.
1 belts are fine. They made millions and still are.
2.Model dash denotes some type of change. and many models have the dashes without telling you. ( part of the game)
3.I like to use surge protectors. Especially on machine with questionable wiring. Always turn off or unplug power to the beasties.
4. NO, Some of the drive parts rest on a table if put directly on them. An easy test for that is to put them on a table, turn the hand wheel and watch under the base to see if conflict happens.
Feel free to conitnue with the questions. All three you are looking at are great machines.