I want to work on an after effects project, and then let someone else work on the same project. He's some hundred km away. After he worked on it, i want to be able to work on it again.
of course. as long as you continue each other's work, you can move the project file back and forth i.e don't work on the same file at the same time - that's what Team Project's is for (only for Team accounts). when in doubt you can create a unique project file for each of you to avoid losing any data (for example MyProject_Roei.aep, MyPorject_OtherGuy). if you are organized this is not a problem. it might be a good idea to save backup version for each time you move the file back and forth (this is true with every project - learn about increment saving) . if you keep the same folder structure of source files in your computers, then finding the missing source files will be easy: Ae project file saves the original path linking to the source files and when you move the project file it may need to re-link to those files. obviously plugins or scripts that are used should be installed on both parties and you should work in the same Ae version to avoid compatibility issues.
Can we do this with two separate regular licenses?
more about all of this here: Project types in After Effects
Did Roei's response help you solve your issue?