I would really like to see mob exp/loot shared as it is in GW2.
In GW2 anyone can attack any monster without worrying about KSing, stealing loot or anything. Everyone gets their share of the exp and loot (as long as they attacked the monster and dealt some baseline amount of damage to it)
I liked this because it promoted helping others with mobs (though in TOS, mobs die in a couple of hits…), and you didn’t have to worry about whether you got kill count for X quest. It clears up a lot of grief trying to get damage done on a monster to get it counted. And you could just kill whatever and grind your heart away without caring about too much.
Since there is such low mob density, only 1 channel at higher levels but still enough players to occupy many spots, a lot of people are pushing and shoving to get their mob kill counts and quest items done. This is really annoying especially with quest items that have a long respawn timer.
That brings me to the other thing, in addition to sharing mob exp/loot, quest nodes should also be shared. In GW2, there are harvestable material nodes all over the map, but they are instanced. So it doesn’t just disappear when a single player goes up to the point - that node is for EVERY player to gather.

