Can you send and receive Cryptocoins from friends or team mates?

No. You can only get cryptocoins by completing acheivements, and sometimes even a small chance on clicking on the emoji on top of the dwellers etc ....

So, I have two accounts, my primary account is CC10 and I am able to gift crypto coins to other players. My second account which is only CC9 however does not show the option to gift crypto. I'm not sure if it's the Command Center level or something else that needs to happen before you can gift crypto, but for sure at some point you can.