If its not on Home depot website then you can not get it.
No groove on the backside
Yes, just be careful not to mar the primer coat.
Many reasons. It doesn't take paint well, and the finish will fail prematurely. It's less stable than untreated/KD wood. It's heavier than untreated/KD wood. It can react badly with aluminum wraps. It's nigh-impossible to find in 1" thickness. Chemically treated wood should only be used near, on, or in the ground: fences, garden boxes, bottom wall-framing plates, etc. Some folks use PT wood for their garage-door jams. And it usually works because you're then able to nail or screw the board near both edges along the length, thus preventing premature warping and cracking over time. If you decide to use PT wood for this application, wait a couple months before painting and expect it to need a re-paint every couple years or so. Summary: Use KD cedar or KD Douglas-fir for exterior fascia and trim. (Some KD pines work well, too.) They are much stabler and much more finish-friendly than PT wood. It might cost you a bit more up-front, but it will cost you a lot less over time.