I'm taking the Open Water entry level at my university.
'...again, my instructor gives me hell.'
I have to laugh at myself because I was worried for a moment, you see I teach Open Water at my university (University of Hawai'i at Hilo) and I was afraid you might have been one of my students. But when you said "her aides" and as I kept reading, I realized I was out of the dog-house!
First of all, I have to commend you for being so aware of how you are underwater. This is not easy to do and those that do, find themselves at the Pro level someday. Here is what I would have you do if I was your instructor (lucky for you this is only pretend haha ).
1) If you are lifting your head up during a short snorkel, that tells me you like knowing where you are and are looking for good visual reference. Unless you are doing this like every 5 feet, this isn't really a BAD thing (or unless you are doing a compass swim and you HAVE to keep your head down). My advice would be try using peripheral vision which granted can be hard to do in a mask. Turn your head side to side to get a lateral orientation to give you a perspective of how far you are. If this didn't work, I would take a spare snorkel and have you stick it between your chin and collar bone, forcing you to keep your chin down to prevent the snorkel from falling. Ahead of time you would count how many black lines it would take to get from one side of the other and use your counts as your distance reference.
2) & 3) You're definitely not alone on this one. Many divers have the "bicycle kick." When I was coaching water polo I would get teens that could not keep their legs straight. So I tied a foam noodle to each leg so they could not bend their knees! This forced them to keep their hips up, and worked the quads because you had to use more muscle to move the leg because of the added buoyancy. Not to mention it was funny as all heck to watch!
But back to diving, keep doing what you are doing and REALLY imagine having pencil legs and not moving your knees. This one is going to be hard to break because it is a muscle memory. In reality, I hardly ever use a flutter kick. If you were struggling with this, I would first have you really nail your buoyancy. In my confined water sessions, when you are not doing a skill, you are hovering for practice. Do your weight checks (especially after a dive on a near-empty tank) and adjust accordingly. Once you know your weight, work on that neutral buoyancy. When you can float there without touching the bottom or ceiling without moving your fins/hands for several minutes, then try kicking. (Much easier to move when you're not on the bottom! )
The fin kick that I use, as well as most experience divers use, is the frog kick. Granted this is a more advanced kick but you might find it easier and much more enjoyable. When I first started out, I would look at tech and cave training videos and note their trim and techniques. After imitating for a while, it became second nature .
[video=youtube;HnJzOkUH7N4]http://www.youtube.com/watch?v=HnJzOkUH7N4[/video]
4) Ascents... ascent rates differ with different training agencies. I teach PADI and their rate is 60 feet per minute. With my experience in tec diving and deeper stuff I personally prefer 30 feet per minute (which is actually more common amongst agencies). Now there are times when you need to have a faster ascent rate, like a Controlled Emergency Swimming Ascent (CESA). I have a feeling she said something to you because of group control. It can be a little hard to manage a class when students are ascending at different rates. When you are finished with your course, ascend at a comfortable, safe, rate to you (within you're training parameters). Remember, your Low Pressure Inflator (LPI) is NOT an "elevator" you always raise it to vent gas and KICK up...
Final words: Trust me, you are not the first student that has said the course goes fast. In a perfect world, I would love to do a longer Open Water class. The only thing, money. Longer class = higher course tuition for students. An instructor should not be "giving you hell," if that is the case maybe it would be best if you let that class go on ahead and you can repeat the confined water session with the next class. If you bring this up to management and voice your concerns, they SHOULD work with you as far as pricing goes...
You have a good mindset so keep evaluating yourself. It might be helpful if you get someone else to video you in the pool so you can see what you are doing while your instructor is giving you feed back. Okay I'm done with my "novel!" Have fun with your course and feel free to personal message me any other questions/comments!