Hi Koray, to answer part two, ships will move as you have to plot the movement in advance every turn. Unless you drop anchor or have no sails. Rest of time you will move as per your card untill you hit something.

First part of question, the collision rules were put in place deliberately to keep friendly ships from being too close to each other, there is no damage for colliding with enemy ships. So easiest way is to keep your distance and dont hit a friend.

My personal rule is that most captains were seasoned sailors so unless they had a new or bad crew, would rarely hit a friendly ship so I move the ship as far as possible then leave the friendly bases touching, the penalty being you could entangle with the rigging of a friendly ship and not move until unentangled.
Hope this helps