I stayed close to that church a few years ago.
Found one nice hotel on Agoda.
After an overnight trip to Halong bay, I was offered & accepted a very good rate at another even better hotel, whilst walking back to my original hotel.
There can be benefits to travelling without a reservation.

The area is very nice. The hotels were up narrow side streets & I wasn't disturbed by the bells.

As for scams, I don't think I was scammed at all in Hanoi. Although during the whole Vietnam trip, there was certainly overcharging for some of the bus tickets.