I agree with the general consensus. The fact that you're concerned about these things shows you really take diving seriously and have a passion for it. That's a good thing! I'd say don't put too much pressure on yourself to be the best diver in the water right off the bat. It's going to take you many, many dives to perfect your craft. And I think that's sort of the point of things like the AOW course. Yes it introduces you to several different types of dives (night, deep, navigation, etc.) but it's also just getting you out there diving. Academically, the AOW course isn't too much different from the OW course. It might go in depth a little further on certain topics, but essentially it's still just an OW course.
My advice is dive as often as you possibly can. That's how you will hone in your skills, perfect your buoyancy, and find your own tricks and techniques that will ultimately leave you feel more calm, comfortable, and confident in the water. When you are those things, your air consumption will be better and you'll find yourself able to spend more time underwater because your breathing will be more relaxed and controlled. And yes, while diving in an area where you are subject to entanglements, low vis, etc. can be risky, it's not a horrible idea because it forces you to recognize those possibilities and formulate a plan of self-rescue. That is actually one of the key point of the Rescue Diver course. Not so much focused on rescuing other divers, but being more aware of your surroundings and knowing how to safely and efficiently rescue yourself in an emergency incident. I actually just completed both the NASE Rescue and NAUI Advanced Rescue courses at the end of June myself and to date that's been the best learning experience I've had with diving so far. And an entanglement was part of it. Remember the first and most important rule of diving....Always Be Breathing. And don't panic.
If you feel comfortable diving in low visibility, you won't get any better practice at navigation than diving where you can't see very well. For instance....when I did my OW class (and also my AOW) visibility at the lake was about 3 ft. Only about 10 during AOW, so I was forced to learn how to deal with it and learn how to use my compass to find my way around underwater. Am I great at it? Probably not like I should be, but better than if I'd learned in the Caribbean where you typically have 150'+ visibility like my wife did during her AOW. "Hey see that reef formation? Swim to it." I'm exaggerating of course but you get the point.
I digress.....I've gotten long-winded and probably bored you to tears. Bottom line is....dive as much and as often as you can. The more you do, the more comfortable you become and the more second nature diving will seem. Neutral buoyancy, good air consumption, etc. will come. Just get out there, get wet, blow some bubbles, and feel fortunate that you have this amazing opportunity!