What is the point of storm troopers?

Rating: 4/10 (19 March 2017)

After watching the movie a question became obvious, that is:"What is the point of storm troopers?". Imperial robots appear to be far superior in combat in just about every possible way and can pilot, do data extractions, etc. Why don't they just use robots?
A much smaller ship could push a star destroyer off it's course and slowly crashing into another one? Can the other star destroyer even move? If a star destroyer can't dodge a slow moving object like that, how would it expect to dodge anything? I guess throwing large rocks (meteor) at one would destroy it, right?
Why would Jyn think it was appropriate to give a pep talk when she was clearly not the leader of the group?
How would a small time criminal know how to use imperial communication tower and why it is not even password protected? Even our phones today have better security.
If the rogue one pilot can use radio to contact the ships outside of shield then why would they need to open the shield gate to transmit death star data files? Radio waves can certainly go through the shield.
If there is a shield can stop physical objects like star fighters then why the death star was not equipped with it? If the shield could stop x-wings getting close to the death star then Luke would not be able to fire the torpedo and destroy the death star, also the torpedo would not be able to go through the shield, right?
I guess kids may enjoy this, but people with basic brain function might think it is just ridiculous.
Other than nostalgia what is the point of this movie? It is as empty as any other teen movies.