Currently, while Ubuntu One can be installed under KDE, Dolphin does not know about it, so it cannot set folders other than Ubuntu One to sync. There is a command line utility, "u1sdtool", which performs most if not all the functions you need.

Setting the keyring password to be the same as your login won't prevent Ubuntu One asking you for it again on login. If you want to change it, install Seahorse, look for it in your menus as "Passwords and Keys", and right click over "Passwords: default", then select "Change Password". The various deleting tricks I've read about don't work for me.

There is an ubuntuone-client-kde being developed, but no clue as to when it will appear in a stable repo.

Any further advice will be welcomed by me and doubtless a few other KDE users.