If I purchase a new computer, install the new Bandlab version of Cakewalk, how do I get my legacy components installed into the new Cakewalk. I have all of my Sonar Platinum stuff downloaded. Will any of these have to be reauthorized? Are there any things from my Cakewalk Platinum stuff that can't be integrated? All my stuff migrated from my existing install of Platinum, but what about a new install from scratch?

Install Platinum first. The Cakewalk Command Center still works and is the easiest way to get Platinum activated. To save time copy all the installers into the Command Center download folder. It will be necessary to install Addictive Drums and Melodyne from their respective manufacturers. Depending on how many AD2 and Melodyne activations are used; it may be necessary to deactivate a PC to free up an install. This is done on your user account on their sites.
 
Once Platinum is installed and activated, install BA and CbB.