If player radar can be enabled in non-pvp areas and disabled in pvp areas at the same time, then I'll support it. But since I dont even know if thats possible, I'm against it.

Considering the huge number of mobs that spawn and the fact that you cant use cave mapping, mob radar would be little to no use at all for detecting spawners. It's not like you can look at underground mobs on the radar and say "oh those ones are in a cave, but that one is in a dungeon" unless you have cave mapping on, or you have already found the dungeon, at which point it doesnt matter. And even if it did make it easier, well then there's your partial economy fix right there (at least I'm pretty sure you were one of the ones claiming the economy is broken): more spawners=cheaper spawners=mtc value drops=diamond prices will go up. I mean, spawners ARE the main reason mtc are worth so much.