I can verify that LRC can reside on at least two machines because that's how I'm operating. Never tried running them both at the same time while on-line but they each work. I only log onto the web with my primary editing machine when necessary to install new software licenses or updates that can't be downloaded and installed off-line....You can transfer the Adobe setup to another machine I believe, but that may well be ‘instead’ and not ‘as well as’ You can always check that bit with Adobe to be sure...
Sounds like you've found a fairly painless path forward. I think once you're past the technical hurdles you'll be pleased with the upgrade to LRC. It is a bumpless transfer with the option of using excellent new features if/when you so desire.Well, my solution is now determined. I'm keeping the current iMac as it is, but will move it to my wife's "office". I will be taking over the iMac I bought my parents about three years ago, as Mom isn't ever going to be able to use it again, and my brother, who is their property caretaker, isn't really usng it much either. Legacy software, other than that photo related, will remain on our old iMac and I'll spend a week or so after I get the new one downloading and installing the specific software I want, including LrC, the Topaz plugins and the newest Mac OS. After learning a bit on our current iMac, it should be fairly easy to accomplish.