Hello,
Just a few notes here, WinVPS support runs a bit different than your standard support for shared services. It is not a managed service unless you purchase a managed ticket for support, however when we are asked to do something like uninstalling plesk, we perform the operation when asked. Upon setting up in the past we rarely ever see anyone immediately move any domains to the server, most seem to use it for a week or so and then start moving, it is not the first time for us to get a plesk uninstall request in the first 48 hours, we typically take it that people tried it and don't like it, and would like to run without it.
When you get a raw vps, it will have base windows 2003 sp2 features. These are listed here:
http://www.jodohost.com/windows-vps.asp Under the Default Installed Software section, then if you install plesk as an option you get the additional software, but it is also uninstalled when the templates are uninstalled. Virtuozzo operates on the basis of application templates if we install them, and it can not selectively install/uninstall applications.
Hsphere is in no way tied to the VPS, anything done in hpshere is only for shared database, billing, and contact management(i.e. mailing updates notices for reboots etc).
This answer is not directly to you but information for all if they should search in the future.