Hello FSDreaTeam!
It's been 8 days since I uninstalled GSX Pro for MSFS and since then I have not experienced any CTD, I'm using Steam (The most stable platform for MSFS) However I am considering re-installing GSX and would like to know how to completely delete both GSX Pro and the FSDT Installer from my PC (just in case). Where are these files located? AppData, Program Files? I'd like to know exactly where the FSDT Installer places these files in my computer.
C:\Program Files (x86)\Addon Manager. Delete the entire folder (this will also delete any FSDT airports you have, so you might want to uninstall them before you do that).
The FSDT installer (or is it called "universal installer"? not sure, remove both) can be savely removed via the add/remove apps function in windwos.
CTDs were/are(?) caused by MSFS, that has been officially acknowledged, so you should be alright.