Yup..you can....

Yes you can use electric toothbrush.2 minute timer is fixed in it which helps in proper brushing for two minutes if you are not able to maintain through manual toothbrush. There are no side effects. Else there are not much difference and both help in plaque removal.

You have total control over toothbrush in manual method, so I think it's preferable. After proper scaling and polishing, you can maintain cleanliness with proper brushing habits.

The effect of brushing depends on the technique of brushing mostly... try to follow proper brushing techniques.. (for suggestions there r many well approved video tutorials..have a look at that) . Rest both mechanical and automatic brushes  can be used in the right way.

Both have equal efficiently if manual brushing technique is followed in a proper manner for an individual.

See using both manual or electric tooth brush has almost equal efficiency to remove plague ,manual toothbrush if use with proper tooth brushing technique will give equal results as electric tooth brush one ,moreover electric one is recommended for special patient (handicapped /mentally challenged) who can’t brush manually properly

Electric and manual toothbrushes both are equally effective in removing plaque. If you are using a manual toothbrush make sure you brush effectively.