Can I use assets like brushes and textures for my photoshop actions if they are free for commercial use?
It’s unlikely to be approved - if it’s a free brush or textue that anyone can download without paying then the added value of conveting it into an action is unlikely to be enough.
Also free (usually) is for a reason and standards may well not be good enough
For example if I’m creating a watercolor painting action,
I will need painting brushes and paper texture, Will it be approved if I use assets which are free for commercial use?
Again - using assets which are not original (regardless of license) and available for free dilutes the value of the submission and increases the liklihood of rejection.
It’s impossible to say either way for sure but you are certainly not improving your chances of approval.
Scan some paper for the texture and buy some real brushes and colors and create your own assets.