[Gower]

The reason why the jedi where taken down by the troppers was this the jedi where losing the force because the sith where becoming more powerfull so when the troppers turned on the jedi they did not sense it coming wich is why they got blown to bits Yoda states that they are losing the force in the second film sheesh do u ppl watch and listen or just watch and forget to listen.
Darth Vader was not the strongest force user to use the force u need will power, endurance and a bit of sense therefore the stongest force user is therefore Luke Skywalker who did not turn to the darkside even when having 10000volts go through him, not to sure about the sense part.