you don't have what Ikeda sensei called "Unity", i.e. you and your partner becomes one unit. there are three pieces that Ikeda sensei normally mentioned: connected, unity, move your inside. they are in that order. see if you can connect to your partner spine. do not struggle at the connection point which most folks tend to do.
What is the difference among connected and unity?
Im often feeling something like extending my ¿balance? Like it were running throught my feet and from the inside of my arm and then to my partners shoulder. is that connection?. Sometimes, and dont ask me how, i manage to full unbalance my partner wit a little twist from my shoulder but i dont know how to move him in any directiob without increasing pressure. Any idea to practice?