Re: Fingers spread or together?
First I learned to spread the fingers. Intent was a better flow of ki.
I now learn to always relax shoulder, ellbow, wrist, hand, fingers ... to create a better connection to the body. (It's smilar to the feeling when practicing qi gong or something like that.)
Endo sensei often explicetly teaches to use the arms this way, to not spread the fingers, but to relax them and to relax also the wrist.
When grabbing, we use lao gong to connect. So wrist and fingers have to be relaxed to make connection.
When being grabbed we use the feeling/kimochi/energy/whatever you name it, doesn't work through the fingers, but from my arm into the grabbing hand (maybe lao gong there). So wrist and fingers have to be relaxed to make connection.
(just to add: Endo does never use the term "lao gong" but just talks of the "palms".)