@pillhuhn Thank you for all of your answers, they helped me.
A small question :D
Can a tran move to a place (1 move) load 2 inf drop 1 -> move back and drop another?
No once a transport unloads any units it cannot do anything else. And once a unit is unloaded it cannot move anywhere else too.
Correct, in both Revised and Classic, offloading ends a TRNs turn.
However, in Classic, a TRN CAN offload to more than 1 territory from the same sea zone (this is only an option with a National Advantage to Japan in Revised). But the dual offloading is FROM THE SAME SEA ZONE. You can NEVER move a TRN once it has offloaded any units in either game.
But keep in mind that a transport can pick up troops from different zones for unloading at a common departure point. Sometimes this is overlooked.