Yes, congregations should be attentive to the whole counsel of God, which includes awareness of the perverse nature of fallen men (e.g., John 2:23-25). Having practices that filter out the grifters and frauds from access to church beneficence is not a slam on the poor any more than having security measures and audits in banks and other repositories of wealth is a display of undue suspicion of the well-to-do. People from both groups need to be accountable.
Giving cash to beggars is easier than inviting them home or to a nearby eatery for a meal together, but is reinforcing bad behavior, not helping them. Likewise for shelling out cash to clever con artists, when it could be directed to those truly in need by doing some simple verifications of the sort you mention.