Yes, glue alone is strong enough even with plywood. But most of the time I pin nail, glue and clamp. The pin nail holes will disappear in the finishing process.
IMO glue blocks are neither necessary nor desirable. If you're worried about squeeze out you can tape off the sides. Finishing the case first, then attaching the FF is also a way to go.
I've used both biscuits and Dominoes they work quite well. Index off the outside of FF and box side. If the outside of the stile is proud of the case, you have take that into account.
If the case sides are hidden you can also use pocket screws.
Last edited by DrRobert; 08-08-2019 at 12:01 PM.