Uninstalling and reinstalling the Origin client software should not affect your installed games nor disturb any of the content or game saves in their respective user game folders in Documents. If you are really apprehensive about this, you could copy or remove your entire game folder(s) from Documents before the procedure and, if you have removed them, put them back again when finished with the reinstall.
If a game folder is not there at all at the time a game is started up, a new one with no content at all (that can then be used for testing if desired) will spawn in its place, but it doesn't have to stay there if that wasn't the intention.