I like the fabric and color. It would make a nice Sports Coat, which is how I would classify this jacket as opposed to a Blazer. The flannel falls in formality between Worsted and Tweed/Corduroy. It can be pushed in either direction by the accompanying shirt, tie, and trousers, making it versatile IMO.
The button stance is too high. The top button approaching the breast pocket and the bottom button at the top of the pocket. For a DB that should be about 2 inches lower for each. A SB can get away with a bottom button near the top of the pocket, but still an inch or 2 below is optimal.
As for patch pockets, there are those who swoon about them. On a SB Navy Blazer I like them, but have one of each patch and flap for S/S season in Hopsack SB. The S/S DB is only a worsted flap pocket, and F/W both SB and DB are flap pocket Lambswool. That is due to the formality difference they confer. A Blazer, considered the most formal of Sports Coats, is unique in being appropriate with patch pockets, at least in SB. My 2 DB breasted Navy Blazers (S/S, F/W), are only flap pockets. But I can see someone else wearing a DB Blazer with patch pockets as a personal idiosyncrasy, I cant in a DB Sports Coat.
Addressing the length, who knows. The current trend, besides short jackets, is to take a 6' 2" model weighing 160 lbs, and place them in a R or S, that is one size too small for the photo shoot. So I would suggest getting the length measurements to more accuratly judge the "real" length of the coat, as it may be OK. Same goes for the arms. Ideally they would be altered to fit the model properly, but for the photo shoot, they always make them too short for their wrists.
Segueing to the sleeves, they seem too narrow. From the pic they are just about letting a barrel cuff protrude. What would happen if you wore French Cuffs? The debate about FC and Sports Coats/Blazers is endless, but I believe and practice that it is appropriate in these times. I celebrate the ability to wear beloved cufflinks in casual situations with my sports coats, and am endeavoring to build a collection of rustic ones suitable for my tweeds.
My takeaway is: If you are comfortable with the price; like the material and color; am comfortable with the sleeve openings; find the true length to be adequate; and are bold enough to wear patch pockets on a flannel sports coat, then you still have to deal with the button stance, which is just off putting. Your choice, your money, your decision. NO ONE is going to see you in that jacket and make any negative conclusions or comments. You will be taken as one of the best dressed men in any group these days. Unless there happens to be an AAAC member present.
It's up to you as to how you feel when wearing this sports coat. Clothes are all about how they make you feel not others.