I agree with just about all of this. Especially with the hunts smh. Staking those would save so much time. I've beaten the game and I'm 100+ hours in. FFXV is a fantastic game that is poorly executed at times. It's easily one of the most beautiful game worlds I've ever played in. The diversity of the areas and terrains are simply amazing. The comradery and feeling of being on a road trip with your boys is expertly executed. The interplay of dialog between the characters really ties you to them. But as you mentioned the fragmented nature of the overall story and the rushed linear ending are sadly not as good as everything you experience earlier. Game probably could've used more development time amazingly enough lol. They took forever but needed forever and a day.
Personally, I really like the battle system and don't think turn based would work well at all in this type of game. Once you master dodging, warping, countering and blindside attacks it becomes way more fun. It feels less like poking a monster and more like getting into a rumble with your boys. Although the camera can be very frustrating, at times being too close or at a poor angle. Fighting in the trees or bushes becomes annoying as hell. As for the magic, I see what they were trying to do but it just becomes tedious. Making your own spells isn't fun but the spells themselves and the added effects are fantastic. Oh and as good as the summons look they kinda flubbed that too. Not being able to choose which summons show up and when is bleh. I've gotten Ramuh dozens of times but Titan and Leviathan only like once or twice.
Overall I'm very happy with the return of Final Fantasy. Glad to know they can still make a great game. Just slightly disappointed that this game could've been a 9.5 for me but ends up more like an 8.5.