As I said on all of your previous posts about this, yes, I do think it should be allowed. If you don't know the person, then don't tpa to them with good stuff.
But if you know that TPA killing exists, then why would you tpa to someone you don't know, with all of your good stuff? It's just another way for people to get things in Factions. If you do have good armor/swords, then you shouldn't have a problem, because you could kill the person you TPA to.
It should exist, in my belief, you just have to be aware with what you're dealing with. But if you don't want to fight, just decline, it isn't that hard. People are always looking for a fight, and that is the easiest way of doing so.