Activity is same to post count? How much potential activity?
Its current activity and post count is 170
I don't know its potential activity but will try to compute it later.
What is the reason for the untrusted feedback? Is the user who gave it has the chance to be in default trust?
Nope, I wouldn't even lend the person in the first place if the account has a neg feedback from a user with default trust.
It is only a untrusted negative feedback