It is possible that I am confusing parts of different game types... Bungie sets it up all crazy...
For your concerns, I may propose that you set the capture time to its highest, as long as there is one defender in the territory, it can't be captured and winning by capturing will rarely happen and be the only way ODSTs have a hope of winning the round (I suppose this would happen very rarely). That there will take care of the kills count as nothing/ scoring... For the whole lives thing, check the respawn settings and be sure to check on advanced respawn settings if you still need to find something, if that doesn't work, check all the traits over again... Have there be no time limit of course...
If all else fails, message back...