I figure that at any point when you halve you round down. This means that some armors are effectively broken when their durability reaches 0.
As for people picking ones that work in their favor; that is the case always.
I guess I was being poor in my explanation. I meant simply that each time...
Personally I'd use it so that at 0 durability it would give half of it's AC bonus. Then have the item be "marked". If an item gets "marked" three times it breaks and no longer functions. This is all in order to keep it as simple as possible.
The other aspect that you could "fix" is to remove...
I feel like you have really nailed the core of this issue here.
As always communicating with the players is key; I always think that GM's should sit down and talk to their players beforehand, and ask them regarding their plans of levels and spells, as well as expectations and general preferences.
I second this post and just want to add that adding minions really adds to the fight for more characters as well. Martial characters tend to be very good at single-target damage while casters can really do big swathing hits on several minions. As well as having a lot of battlefield control and...
Warlock and Cleric.
Something me and my brother tried before, and found it quite fun.
I really like the rage idea as well. Gives the whole world a fun twist.
It all comes down to how you want your players to act. If you find the talk to be disruptive; I think you should first talk to them and suggest that they should reduce the "meta"-talk.