We have some of the same problems and limitations you face. Such as wide enterprise distribution (in the thousands), users without Admin rights, enterprise testing before acceptance of new versions, pre-requisites, etc.
We do not use an automated process because of a lot of the issues you raise and we have also tested the Citrix route. The key with us is to have at least a period of time when we support two versions of ArcGIS Explorer. This gives the localized System Admins time to upgrade user workstations. Such as build 1200 and 1500. After a certain percentage of users are upgraded we drop support for the older version and prepare for the next upgrade.
Our â??upgradeâ?� process is to run new versions thru testing for enterprise acceptance. Once accepted, the new version is made â??availableâ?� for enterprise deployment.
From there a user can put in a help ticket to have their version upgraded. We have System Admins at all locations and they have rights to, as you say, uninstall previous versions and install the new version and any required frameworks
I know this is not the answer you are looking for but at least you know youâ??re not alone in wide enterprise use of ArcGIS Explorer Desktop.
I will be watching this thread to see if you are successful on finding an easier solution to enterprise distribution, installation and upgrading of ArcGIS Explorer Desktop.
Thanks,