Yoper,
I checked the rulebook and the questions are not addressed specifically - but this is how we have played it in the past and I'll add these to the next round of edits unless folks object (too bad this did not come up last week before I posted the rules):
I don't think Dan is going to be happy with me. . .
Only the Western Allies can move
and trace supply through the Panama Canal - so the Soviets are out of supply.
Out of Supply units can not strategically redeploy.
British units need to trace supply back to a Western Ally supply source, so the British fighter in China would be considered out of supply.