If we are at all interested in having our server be authentic to the campaign setting that serves as its source, then no place should be safe at night, especially the Western Outskirts. It's easy for people to tell the AMPCs/MPCs that they shouldn't be doing things in the Outskirts, but imagine you're a vampire -- there are times where you struggle to find someone or a small group, separated from the rest of the server, out on their own. You waste most of the evening trying to one or two or maybe three people isolated from the rest of the server, and when you finally find this group, you have roughly twelve minutes to do your thing before dawn arrives.
It's quite easy to judge how an AMPC/MPC should be played, when you've never played one. Those who have been given the privilege have been tasked with reinforcing the server's atmosphere, and while people often think that the Western Outskirts ought to be an enclave of weird outlander stuff where what would normally apply to the rest of Barovia doesn't, it is not, nor should it ever be.
Reinforcing the setting is one thing, telling players they cannot influence the setting is another. If you have a concentration of people in the area from the well, along the wall up to the transition and east as far as the transition to the Vistani camp what are we talking about? 100 square meters? Players have no right to fortify that area if they so choose and make it the one safe island in Barovia? I strongly disagree.
I have watched monsters single handedly engage a dozens plus players many of whom exceed the lvl 12 range and leave with a field bodies. Vampires especially have almost no risk in these situations. The Harbinger and his crew were also not a band of lvl 8s, they well exceeded the level where you are getting xp penalties. So we should just make the Outskirts easy pickings for antagonists?
The very thing you describe your vampire going through, searching all over for victims, is the very same thing you want to subject lvl 12+ players to. Forcing them out of an area they know they can find rp.
I have had my character go all over the server, Port, Mist Camp, Barovia village and not been able to find anyone to interact with, this is not just a monster problem.
I understand it would be more ideal if the characters were not there and I have provided constructive suggestions on how to improve that. You must provide an alternative. Very few high level characters are in Vallaki because they want to bully low levels, most are there despite the inconvenience because it is the only place they are getting rp, access to plots and so on.
Monsters can go to dungeons, the sewers, follow the main road ways. They do not in my opinion have the right to dominate the outskirts, but of course they are welcome to try and on many nights they do.
The essence of your argument is your Monster's rp and contribution are more important than normal players are and I do not think that is valid. I know you are a great player and a fine antagonist and I know mpcs play a vital role in enhancing the setting. I might suggest to you that mpcs could by part of the solution by luring players away from the Vallaki.
My Paladin has extensive files on your Port Vampire as an example, has gone there several times to look into it. That lured her away from Barovia. The problem was there was nothing going on there when I got there. If we thought only low level monsters were haunting Vallaki then many of us would be happy to leave those problems to lower levels, but all Monsters pretty much are in Vallaki.
Obviously the Port is a solution. The staff need to make it a draw. It has been in the past and now it's not. High levels do not want to be in the Outskirts, it's very far from the dungeons they go to and they know they are cramping other players opportunity to shine, but it's better than nothing and better than being alone.