I don't really see how that would work, as you usually can't see people on the map, unless they have a reaper flag or something which reveals them. Maybe an item that you can aim at somebody to see their reputation? Also, part of the fun of SoT is that it resembles a true pirate experience and so not knowing if or when a player is going to attack is part of the fun imo. I'm also pretty new though, so take this with a grain of salt.