Questions about the load out menu

Hey everyone, just wondering if I can swap aberrant forms? For square and triangle, there are different slots. So all I need to do is find Living Shards to craft another form and then I can always switch in the load out menu right? Or do I have to enter the gap every time to manually reset?

Can I swap combat abilities as well? Just wondering why I need R2,/L2/R1 if all we get is the one combat ability.

Just a bit overwhelmed! Thanks