viable upgrade path, changes in behaviour

Hi

I'm sure that I'm not the only one that'll be asking these questions.

I have been using Voyager for a long time, the last upgrade was to 12.3, at which point I just kept using it as is.

As the new, free, version 16.x became avilable I got a copy, and it's being tested right now on a VM, before I upgrade the production copy.

I have a couple questions:

1. Where can I find a clear script for an in place upgrade from earlier (in my case 12.3) to 16.x that will preserve sites' data
2. I have transferred site settings using export from 12.3 & import into 16.x
   1. The settings get imported, and are working, reserving acocunt and password data
   2. I have found out that secure link behaviour has changed, a site where I was using 'AUTH SSL' port 21 using 12.3 had to be changed to 'FTP over TSL Explicit' port 21 when using 16.x
   3. I have not gone past this point, testing this one site
   4. So... when can I find documentation about change in behaviour of Voyager?
3. Thanks.. David L.