Is AP Psychology considered a science course for college admission ?

At my school, it's considered a social science class, along with the history classes. This is probably because of the emphasis that physc has on memorizing theories and people instead of knowing the science and the workings of the brain, although that's in the curriculum too.

If you want an easy science course for senior year, consider environmental science. Out of the higher level science AP's, bio is the easiest in my opinion.

It depends state by state, it could be catagorized as either a history class (no clue why) or a science class. I suggest that you ask a school advisor if you have access to one or to look it up independently to confirm if it is one or not. Hope this helps.