Right now, people are able to maximize abuse out of this by constructing gates in many places- even if it's horribly ugly if they start constructing small gates in front of homes (Don't even need to lock them, or leave them closed)- they become nigh unraidable due to having way too many spots raiders can't touch due to.
I'm sure there's also a lot of abuse points, but right now there's no downside for a defender to spam gates.
So, to alleviate this- there should be a secondary cost to this. Perhaps the gates that cause this specific "visitor" debuff are special gates, that are also expensive to create (Lots of resources, gold/silver?) so players will minimize the amount of them that they place around. Alternatively, there could be an authority drain based on the amount of players that freely enter and leave a claim after time (Effectively allowed you to 'chip' down on abandoned claims, or raiders to wear away at a gate and force it to close otherwise the owner loses all influence). Though to prevent alt abuse on a single gate, the process should probably just cost an extra amount of influence based on the total traffic over some time- regardless there needs to be some changes made due to the potential abuse of this system currently. Another idea is to have a limited number of gates being selected as "entrance" gates based on the size of a claim/influence of a claim, and not being able to be changed more than once every 24 hours.
It's a fine idea otherwise, and in a perfect scenario (Where players don't make gates for extra protection) it can be a fine mechanic.