Regarding loot - As dedude and Valefort said there are some changes coming and, if I am not mistaken the changes are not limited to just making everything once per reset. There were also some issues with area/chest levels which prevented higher risk/more difficult areas from having the appropriate chance of spawning better loot. Obviously testing will be needed, but theoretically chests/corpses should be more rewarding IF the player is in a CR appropriate area. The goal is to keep players in level appropriate area's after all.
Regarding Bosses - Simply put, for a given level range, unless you are a power build or can get an appropriate group together there are certain area's that are far more costly to go adventure in, even if they are CR appropriate. In these cases players of certain builds are actually kind of pushed toward redoing the same area's if they want to level without high risk of losing XP and, worse if they are the few who don't take the penalty and if no one raises them they RCR to some other character or start over. Further, as Calodan pointed out there is no rule against players redoing an area, including the boss and thus there would be no reason to create any development effort to track or stop it from happening. If the admins wanted to do that sort of thing it would be a mistake in my opinion as some of the player base that rely's on certain known area's would have the option to either brave an area they know is too difficult (which could lead to rage quit), log in as a different character (which is not the desired outcome), or just log off (also not really what we are aiming for).
In general, those I have run in to (like Calodan) are more than happy to take a 30 minute break if they are 'farming' a dungeon/boss area to allow another individual or group time to RP, loot, run the dungeon, take on the boss or whatever. My suggestion would be to In character make it known that you/your group is looking to take on whatever and, if that doesn't get the job done just send a (friendly) OOC tell to let them know you'd appreciate if they took a break or went elsewhere so you could have a turn. If they get salty and/or refuse, continuing to farm an area they've been in for the past hour+ then screen shot the conversation and send it in. I have a hard time believing it would ever get to that point though... Grinders just want to be left alone to their looting/boss fighting/xp grinding/questing/whatever so in general if asked to allow for others to use the area they're more than happy to oblige.
