I'm not sure a scope is going to be a good idea for a carbine class. Most of the ones I've seen are pretty up close and personal. I would inquire from the instructor what the maximum range is, and what kind of accuracy they're trying to achieve at those distances. (e.g. is it quick center mass hits at 100-200 yards, or is it aimed head shots at those distances?) If there's a lot of precise distance shooting, or a lot of distance shooting period, I might look for another class. As civilian and law enforcement shooters, we're just not going to be likely to ever need those skills. We tend to run into trouble at less than fifty yards, and your Aimpoint is THE PERFECT optic for that.
If you're going into a carbine class, I would be more concerned about my rifle. What do you have that Aimpoint mounted on? Carbine classes are notorious for destroying guns, so you don't want to go in with a hobbyist level AR, but likewise you don't want to bring your 3k dollar custom job either. Personally, I would opt for an LE6920, as it's cheap and likely to survive, and if it doesn't then you've only lost a 250 dollar barrel. Then bring your other AR as backup just in case. Definitely ask whether they have extra guns on hand, and if they charge extra to use them.
If you think you still need a scope, then I have some general advice, though I couldn't pick one as being the best. First of all, stay away from Vortex, Primary Arms, etc. Second of all, don't settle for 1.5x. Whatever you do, get a true 1x, or you will seriously regret it when shooting at close range. Third thing is pay close attention to weight. The 1-8x scopes especially are monsters. My personal preference is for Trijicon. They're built really well, and the glass is amazing. There are lighter options with better reticles, but they all cost a lot more.
As far as reticles go it really depends on what mag range you opt for. If it's a 1-4x, then second focal plane is perfectly fine, but don't get some complicated reticle because you won't be able to use it. If you get a 1-6x, I would highly recommend a first focal plane, and it's an absolute must if you go for the 1-8x. Even with the 1-6x and 1-8x, though, get the simplest reticle that's available, ideally a straight forward mildot style one without half gaduation hashes. I don't know what the deal is with scope makers trying to cram all this stuff into a reticle that's going into a scope without enough magnification to be able to see it.
On the mount, I do like Bobro. I just don't see the average person needing quick release mounts. I don't really see anyone needing them, unless it's a scope that gets moved around a lot, like you use it for load development or something. My favorite mounts now are SPUHR. They're rock solid, and the 6 screw rings give me peace of mind when mounting a pricy scope. That said, a Leupold non QD cantilever mount is like 150 bucks and it will do the job just fine.