rmalarz Loc: Tempe, Arizona

Peter, I've installed CC and still have CS6 on my iMac. Both run quite OK. The add-ons do need to have their shortcuts copied from the existing PS folders to the equivalent folders in the CC install.
--Bob

artBob Loc: Near Chicago

Sorry, Bart, but I cannot help you with FTP program. My FTP file transfer is done with Dreamweaver.
Your solution seems fine to me, and I'm glad you can update your site.
Bob

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You got me at "dreaded rental" - exactly what is dreaded about a different form of payment for using software?

1. Assuming he is installing LR Classic - installing CC will not wipe out current software. However, in the case of Lr, he will be given the choice to import to the new one, but there is no reason to not do that. The current software has a new process version, works better and has many features and benefits not present in previous versions. There may be a reason to keep an older version of Ps, but chances are he won't use that much once he starts using the current version. Little to no justification for using 6 yr old software, or put another way, software that has undergone seven major version upgrades.

2. Can't answer that. If - a big if - his machine configuration can run it, probably maybe. He needs to become computer literate. It's like driving a car without having taken driver training. Bad things can and will happen, computer-wise, anyway.

3. Without knowing what plugins you're referring to, it's another unanswerable question. Ideally, it will all work just fine. But Ps 2019 has stuff in different places compared to CS6, so there could be some confusion. Again, computer literacy is important, or a checkbook with a nice balance, to pay for someone with those skills to help out.

artBob Loc: Near Chicago

My experiences confirm Gene51's points. A little harsh, perhaps. Some of us here will be willing to help the poster become "computer literate" in this area. Also, I have found google very helpful, finally, with specific technical problems.

Bottom line for original poster: Subscribe to Adobe CC programs. Ultimately not more costly, works better, and automatically kept me up to date without having to check and update versions continually. Any more questions, PM me, and I'll give you my phone number.