Most of the time i'm on OS#2 i always hear "i'm friendly". True i do respect when they are doing achievements and helping others, but honestly its called a DEATHMATCH arena for a reason. It gets to me when these "friendlies" keep constantly complaining about getting killed. Most of the people that go to the arena just want to fight/battle, but these guys get in the way. Then a huge argument starts.

Another thing is when people idle on spectator. It really makes no sense in a way, and personaly i think they are just taking up space for other who wish to join.

As for the second issue, everything I have read indicates that you cannot find items while in Spectator, so they are indeed just taking up space.

You can get items while idling. If the server is full and you know that some other players want to join, you have my permission to kick a spectator if you have that ability, or let me know and I can kick them if I am available.