Haven't played drupal for some years, dunno if it handles those "upload .pdf files" out-of-the-box ... but for giving rise some ".pdf files" "thumbnails", you may check either the traditional imagemagick or the neo graphicsmagick, afaik ...
I would prefer a separate folder for customized service that parallel the uniform server, although the database export/import is still necessary during a US upgrade ...
Vhost is serviced by apache, so it would be wiser to post at least the vhost section in your 'UniServer/usr/local/apache2/conf/httpd.conf' file ... Once apanel failed, you may maually check/edit that file for sure ...
It might be a nice idea to run the scripts under that two folders from within a CMD Prompt ... Just read and you may see that "a_diagnostic" is the folder for diagnostic purpose:
a_diagnostic/1_port_check.bat
a_diagnostic/2_Apache_program.bat
a_diagnostic/3_Start_MySQL_program.bat
a_diagnostic/4_Stop_MySQL_program.bat
a_diagnostic/5_Start_Services.bat
a_diagnostic/6_Stop_Services.bat
a_diagnostic/server_status.bat
and "alternative_control" for alternative control of services:
alternative_control/remove_drive_w.bat
alternative_control/run_on_drive_w.bat
alternative_control/Service_Install_Run.bat
alternative_control/Service_Stop_Uninstall.bat
alternative_control/Start_2.exe
alternative_control/Start_Cron.bat
alternative_control/Start_MySQL_Console.bat
alternative_control/Start_Server.bat
alternative_control/Start_UniTray.bat
alternative_control/Stop_Cron.bat
alternative_control/Stop_Server.bat
alternative_control/Stop_UniTray.bat
Unless you put your clone under a path with space (U0020) ...
Unitray "should" appear in the System Tray, with the number of server(s) running, something like a white number on a blue box ... Besides, there are two folders to play with yourself, "a_diagnostic" and "alternative_control" ...
Well, were it true that "it grabs the first block from the ip as port", the parser might fetch the first "Listen " directive, such that you may swap the two "Listen " rows ...
Yep, Carbo and Nano are compiled from the same source base with different VC clones like you mentioned, such that they rely upon different run-times as well ... As if the version comparison is kidding in Carbo ;-)
As if another instance of the IP stack priority in Windoze se7en, where IPv6 is preferred over IPv4 ... Please refer to either this or that as well as further references, if you like ...
But obviously you get everything provided by US out-of-the-box on a Linux box, and with a rolling released distro like either Gentoo or Arch, you get automatically upgraded, right ;-)