Hi there,
1. If you would like to move Captivate license on another system, then on the first system, Launch Captivate , go to help > deactivate, Captivate will get deactivated from first system; then install Captivate on another system and enter the serial number, it will get activated on new system (Internet should be connected while deactivationg and activating).
2.Yes Captivate 5.5 created projects can be opened in Captivate 6 or 7.
If you would like to open projects created in Captivate 5.5 in Captivate 6 or 7, then first make a back up of original Captivate 5.5 project, as project once opened in Captivate 6 or 7 will not be opened in Captivate 5.5 again.
Procedure: Launch Captivate 6 or 7, click on file> open > then browse that Captivate 5.5 project and open that.
Thanks