I want to marry the man who sent me proposal. I followed his Instagram to learn his beliefs, and he followed me back to see my interests. We do not message or talk privately; we only view each other’s post. Is maintaining this mutual following haram or makruh?

I am not in favour of this at all, and I say close the door altogether. If the proposal does not work out, you might keep checking his profile or even message him later, so close the door. You want to communicate once or twice before getting married, then he speaks to you with your mahram present and that is it. Afterwards, you move on with the marriage procedures.