A: There’s no need to dry the post prior to installation. This item is not kiln dried. thanks
A: Generally these are bought as 2&btr but some mills use other proprietary grades. We re-sort all of our lumber prior to treating as well and remove pieces that don't conform to our internal specifications.
A: you should always try to not bury the cut end. In either case you need to use end cut solution to treat all cut ends of treated lumber. thanks
A: should be fine just be sure to leave gravel as a base so water can drain out of the bottom