I doubt this is solely attributed to Thor's acquisition of Tiffin, lack of quality is an issue across all manufacturers that has plagued the industry for decades. I always hear buy this or that brand, like it actually matters in terms of amazing quality and workmanship. Several companies that I have worked at have been acquired, we just continued to do our jobs like always, any real changes were couple of years in the making.
Sorry to hear of your new RV misfortunes, following along over these past few months I always knew that this scenario would come about, more so since the complexity of issues that can occur in this category of RV seem boundless. It is rare indeed for any type of RV to be issue free during first couple of years of ownership, hopefully they will get all the kinks out soon and you can thoroughly enjoy your beautiful RV.