Re: Gripů wait for me!
I actually try not to use my fingers when "grabbing". The connection of a strong-fingered grip is pretty illusory, and I find it more effective to work on maintaining kokyu with just my palm on nage's wrist. It is hard at the beginning, but you are eventually able to feel and guess what nage's next move is going to be, even in jiyuwaza and randori. In fact, even more so then (for me anyway), since I can't lazily guide nage through the technique with suggestive ukemi (it happens sometimes by accident, to all of us, I think).
I think that the only helpful advice that comes to mind is this: if you are concentrating on holding on to nage's wrist with your fingers, you'll have that much more trouble maintaining a connection. As weird as it sounds, the grip (and paying attention to it) works against staying connected.
Hope that helps a little bit!