Normally on MacOSX all you need to do is go to the application folder and send the particular application packages (or their program folders if they have any) into the trash & empty the trash. If you wished to keep them I guess you could zip them first & trash the unzipped programs.
I guess there is a chance opening WS is somehow triggering a reaction from one or more of those programs. I just tested WS & LPE open at same time in another account without issue however.
Preferences folder is where you suggested.
Deleting preferences folder on MacOSX. The example is LimeWire, but instead find WireShare's preferences folder.