Looks pretty awesome to me. Regarding your points:
Seriously, vertical terrain adds so much depth to combat in literally every genre possible that any camera issues are more than made up with an increase in tactical options. The camera can get a bit "bobby," jutting up and down, but you hardly have to check every angle. Remember, these people have never played the map and are getting used to tons of new features. A possible option would be a way to temporarily lock camera height so you can move around the map without getting motion sickness.
Graphics look pretty solid to me. Textures look leagues better. Sure, there's nothing particularly special about this arena map, but it's a pre-alpha arena map. To be honest, I don't think there was anything insanely unique about the original D:OS graphics in general either -- mostly character design, sounds, and the sort of goofy vibe set it somewhat apart from the standard RPG look. It was solid, but not some signature look that has been abandoned. The UI looks kind of generic but, again, it's pre-alpha, and that 30-slot bottom bar is sooo much more functional than the 10 limit.
Simplified AP can go either way for me. I can understand why they went that direction, but more variation in AP costs does create different ways to balance. Overall, I think it will be an improvement.
Movement has always cost AP... I didn't see any Man-At-Arms AOE spells (besides like, phoenix dive, if that was even a warrior spell). That warrior also had geomancer spells.
I think the new bar above the health is some kind of new armor system. Some skills penetrate armor, heal armor, etc. I don't quite understand it, but will be explained in due time.
Returning to vertical gameplay goes, I'm really hoping for more skills that directly take advantage of height advantage and complicated terrain. Stuff like grappling hooks or a way to scale something without a ladder, perhaps just little vertical paths (e.g., vines) that are ways for more dexterous classes to scale. Ways to knock off players heights for heavy damage, a damage bonus for teleporting an enemy off a height, stuff like that. Also, cone attacks really need to be able to be aimed vertically (though maybe they can be in a way already, but it seemed like that ooze, Margaret, lol, couldn't hit that enemy on the height with that ooze spray spell).
Also, variety in projectile arcs would be wizard, including a really vertical shot where you're practically shooting straight up, so you could hit someone behind a wall, or even a sideways arc path.
I'm also digging the new surfaces and how you can curse or bless them.
