So here is how I generally handle land claiming, with a few exceptions:
You need to give the owner at least 3-4 weeks notice before it can be transferred to you, unless the owner was banned. If they don't respond, then you may claim the land. The land cannot be something nice. In that case, you could request to get permission to build so that their land is properly integrated into what you're working on. Also, you can't randomly claim people's land. It has to be land that is getting in the way of something you are already working on. All of this is negotiable, depending on the situation. Therefore, I personally handle land claiming on a case-by-case manner.
Did you start anything near this town? If you just want to take it over, than I cannot allow that. The land around this town is mostly uninhabited, so I'm sure they meant to keep it that way. However, I need to know first if you started anything near.