Hi - first post! Thought this would be a good first thread to contribute to!
Forward drag - as to whether the blade should be on the ice, that depends on how deep your other knee is bent. The lower you go, the more you come off the blade and more onto the side of the boot (great for that scuffed look!). The leg should not be lifted off the ice, but most of your weight should be on your front leg.
Forward crossovers - it doesn't matter at this stage how big the circle is. If you are doing Skate UK, chances are you are using a hockey circle as a guide which is a good place to start. If you are skidding about on your edges then it might be cos your blades are too blunt. However, it is quite easy at first to lose control - I suggest breaking it up into steps in your head, ie. "push, crossover, uncross" and keep it at a nice even rhythm. It is all too easy to start rushing it. Keep your knees bent!
3-turns (outside 3turns?) is a lot about upper body control. You start off on your forward outside edge and in a controlled way, twist your upper body (keeping your arms, shoulders and head as a unit) in the direction you want to turn. When you want to turn, unbend your knee slightly (of course, you will have had a nicely bent knee up to this point

) to take the weight slightly towards the ball of your foot, and just let your hips catch up with your rotated top half. You shouldn't need to force the turn.
Okay - think I've ranted on enough for now!