Thanks for the help!

I just started playing Axis & Allies 1941 and I need a little help with some attack scenarios.

Say I have Russian Units in Caucasus, Russia,Karelia and Archangel and I want to attack German held West Russia.  Since all four are connected to West Russia can I combat move units from all four territories into West Russia and attack?  Also if I had a Russian bomber and a fighter a couple zones away could they join in as well?

If I moved American troops and planes to the U.K. can they take part in an amphibious assault on West Europe when its the U.K.'s turn?  Do the American troops become part of the defense if they are in the U.K. with British troops and the U.K. is attacked?

If German troops from West Europe did an amphibious assault on the U.K. can fighters and bombers from Berlin be part of the attack?

Japan is in SZ45.  If a bomber leaves Japan is the first move SZ45 or SZ44?  When arriving in the Western U.S. is the last move SZ42 or the Western US.  Basically how many moves does a Bomber make going from Japan to the Western U.S.?

Thanks in advance for any help provided!