As for why the Order's still chasing them, I think it might be because it's the only tactic that works. As has been said, the Order will not force Bree to do anything against her will. So, they track her down and chase her. It's probably more exciting than a standoff (though that would be cool--cue
The Good, The Bad and The Ugly theme music

), as well as more exciting than seeing Jonas, Bree and Daniel cooped up somewhere and doing nothing. That's why I think that if Bree and company can't fight the Order, can't run from the Order and can't join the Order, then they should
secretly infiltrate the Order and expose it from the inside. Bree's exercising her free will, the Order thinks they have her, and everyone's happy until the Order gets what's coming to it. Seriously, I really think this has to happen. Otherwise, this will be like "Groundhog Day".