Two suggestions here:
1. Make some kind of penalty on permanent record for team-hitting. Maybe it would be shown beside Kill/Death numbers. Maybe even go as far as make your items have higher chance of breaking that round. This would stop many (not all) players from taking very stupid chances. Like archers shooting at someone surrounded by his teammates.
2. Change the upkeep system so people don't have to think about the time while in battle. Stall for an extra tick and so on. Would recommend just giving exp/gold at end of round calculated to the second.
My 2 cents
Arkonor
