I am genuinely curious. Does your husband do the same routine when he travels? I don't mean to single out your post but you have listed some very specific routines, and say that you are not paranoid, and that your husband travels quite a bit.
I live in hotel rooms about 300+ days a year. The majority of hotels around the world use duvets; in fact WDW is about the only place I stay which still uses bedspreads. I do remove those. I use the tray table on an airplane, and even the airplane blanket if I forgot to bring my pashmina. I walk barefoot in my hotel room, put my clothes in drawers, make coffee in the coffeemaker, and actually use the hotel room for the purpose for which it was intended. I even use the remote control. I have stayed in some very questionable places over the years, but I haven't wrapped myself in plastic or taken extra precautions.
I have a chronic illness which results in a compromised immune system, but I very rarely get ill. You do realise that you are doing your family a disserve by NOT exposing them to things? And as others have said, how to you control their actions in other public places? I truly am not trying to 'pick' on you however I am very concerned about our future when I read people overusing antibacterial products, the over prescribing of antibiotics, and the failure to expose people to germs.
I have been all around the world and stayed in places and used facilties which are not quite the German standard of cleanliness. There is of course a reasonable amount of care that we should all take to protect ourselves, but going overboard tips the balance and works against us.
And I do in fact have a lightweight duvet stored in my OL for WDW; not because I am squeamish but because I cannot stand the habit of sleeping with sheets and blankets (which again only WDW seems to use anymore)