Maybe I had a similar issue about the Toolset where the Uninstall.exe could not be written which resultet in me being unable to uninstall the Toolset. My solution to this was simple and silly like this:
The setup wants to write the file to "C:\Program Files (x86)\Common Files\BioWare"
The folder doesn't exist. So I created it manually (just the folder "BioWare"), retried the installation (or just the step where you have to choose between ignore / retry and maybe abort? Anyway, at the end of the installation). It worked this way. I was able to uninstall the Toolset and the SQL-Databases.
I am happy.