Tips for blending takeaway and backswing

[downbylaw11]

Ok, so my biggest concern that I'm having trouble feeling my way around is the takeaway and backswing.  I'm trying to develop a one piece takeway, but I have a really hard time blending it with the backswing to the top during a full swing.  I can check point it all day, and do it in super slow motion, but anything faster than 25% speed and I feel like my hands start going off the line and when I see my swing on video at full speed, what tends to happen is im on plane to waist height, but then the club swings too far to the inside, before finding the correct position again at the top.  I guess it could be worse since I'm usually at the correct position at the top, but I feel like I would improve consistency if I could stay on plane the entire time.  

obviously when im going through checkpoints, I can just turn my chest/shoulders, and be at the perfect position, but when doing a really swing, should I start my blending of the backswing before I get to that point, because I often feel like I get stuck between 2 positions when I go from one point to the next?  or is it just a situation where I need to slow it down to the slowest levels and do 1000 reps until i can get up to full speed? 

drills? tips? 'feels'?

[iacas]

Video would be helpful here. Who knows if "the correct position at the top" is indeed that, and who knows if the club or your hands/arms have momentum that are carrying them off-position but they happen, at the top of the backswing, to pass through a "correct position."