Question 1: The plugs do not need to be removed, but it is easier to turn the motor with the compression being released out the spark plug hole.
Question 2: jacking up a wheel with the (manual) transmission in 4th gear would easily turn over the motor, but if you are trying to line up the timing marks or some other similar task, this would be a 2 man job. it is easier to use a 27mm (1-1/16") socket on the front carnk shaft balancer bolt. this way you can watch the timing marks as you turn the crankshaft with a ratchet.
Jacking up one wheel was a fairly common way of cranking Ford cars before the introduction of the electric starter.