do you have potato starch.

I do not know but they do have a lot of variety

Unfortunately I can't say with certainty but they do have a modest selection of other of Bob's Red Mill ingredients (coconut flour, tapioca flour, almond flour etc) so i would be surprised if they didn't carry it

Unsure. Sorry

Don't know sorry.

Sorry,not able to help you about potato starch.

I don't know about that, sorry.