You get a free action for every 200 points or fraction thereof.
What does fraction thereof mean?
How many actions do I get for a 500pt base for example?

Also do attacks count as combat actions?

0-200: 1 action
200-400: 2 actions
400-600: 3 actions
etc.

Attacks and actions are not the same thing, but usually the only way to make an attack is to do an action that allows an attack to happen.

You mean
0-200: 1 action
201-400: 2 actions
401-600: 3 actions