Yes, UKServers are a great company (based in Somerset) - they always know what they're talking about.
Which is more than can be said for me.
Changing directory names in a solution like PowerStore can open a can of worms - there are many interconnected facets all needing to know where each other are. It would take someone like Ray, Jason, Eric or the WA Experts to fully know the impact of such a change and how to where the references need to be changed in the php files.
It may be that you just need to change the reference in your PowerStore200/WA_Globals/WA_Globals.php file to your renamed directory, but I wouldn't want to send you down a path that someone else might have to unravel later on. The menu system could also be a problem.
What happens if you revert back to the default name and configuration? Does your site load OK?
I would suggest reverting back to that, so it functions OK, then posting a new thread to ask for the steps to change the directory name.
If you do experiment, I would make a backup of all your site files/structure beforehand so you can revert to it if necessary.
For anybody who may have a good idea what to do and might jump in here, a link to your site would help them.
Sorry not to be more helpful (if it were me, I'd leave the default names as supplied!)
PS - There's a UKServers in Somerset (where I am) and also one in Rugby!