Re: improving footwork
Larry made the distinction between "positioning " and "footwork", which I think is important. It is essential to be in the right position for a technique, but there may be room for compromise regarding how you get there - i.e. footwork.
Ki Aikido attracts a lot of older people who can't always move in the way that the technique would seem to demand without taking an extra step or two. To my mind, it is better to adjust the form (footwork) of the technique than to compromise the structure of one's form. After all, freestyle aikido is supposed to be formless.
Having wrestled myself with the issue of how much attention to give to my feet, I have found that moving from my centre into the correct position whilst trusting my feet to do their own thing works best (although paying attention to where your feet go is generally necessary to learn a technique).
By concentrating on position more that footwork, you can learn a technique, then work out exactly what you're doing later. This seems backwards, but I have found that it can make learning both faster and more enjoyable.
Thinking of your feet can trip you up, but this is a question of style and principle. Tai Chi people build up from the feet, and it works for them, and Bruce Lee emphasised footwork. Each to their own.