Your licenses should be somewhere in your inbox or some userprofil on the vendors homepage. Only you know that.
Upgrading to 10 will not destroy those things. Neither programs or other stuff. But you never know. If you haven't backed anything up you are sort of asking for it.
Anywhores, I'd just choose "upgrade" (to make sure your HW-id is registerede with Win 10 - although your 8 key should be valid) and the clean install afterwards. Upgrading sucks, clean installs are the way to go, IMO.