Not sure if BT will kill mites (information on the internet is conflicting). BT has to be ingested by the bug, and it is not systemic, so it has a limited effect on sucking insects like mites and thrips. Pyrethin will kill them both, but I would not spray it if the plant is in flower. Pyrethrin is best sprayed at lights out, as it can burn leaves. If you've got mites, I'd spray for them first (you may have to do it twice, about a week apart). Then let the plant recover a bit and do the BT. BT won't burn the plant, unless it has an oil or soap added to it.