Hey thanks for the suggestions, I wasn't aware of BetterChat's ability to add tags above player's heads - that sounds like a great way to display it, I will definitely add that to my board to look into. I originally had the same idea about the PVP bases, however, I'm not sure if I want to pursue it again - it can make a map very cluttered and based on my tester's feedback I think a lot of servers wont use it because they don't want player base locations revealed. The command to show player modes is definitely doable, I'm not sure how much that will help on moment to moment decisions though (like when you're out raiding or in a fight). These were great though and realistic ideas.
As for the marker, it only refreshes every 0.5s for performance, I could make the interval configurable so that you can set it to update much faster if you have the hardware - if you set it to something like 0.1s it would appear almost instantly when you look at someone. Furthermore, under the "Marker" section of the config there is a "Distance" property that you can change so that it will appear when looking at a player from further away.
I added your suggestions to my internal suggestion board, so I'm going to mark this as closed (since its not a bug). Thank you for the feedback!