Unlike Talend Open Studio (TOS) for Data Integration, TOS for Data Quality neither start with a splash screen with project and workspace choices nor permits to change the working project in the Studio. :(
I would like at least to change the workspace location, not to use the default one which is under the installation folder !
Well, it is not possible unless in commercial editions.
See : https://jira.talendforge.org/browse/TDQ-7728