The only coaches I have ever seen where you can't access a main area of the motorhome, is the bath and a half models. Those generally have the bathrooms in the rear and I think part of the reason they have the half bath is because with the bedroom slide closed you have to crawl over the bed to get to the rear bathroom. Other than that, I have never seen a motorhome yet where the closed slides block you from getting to every place else in the motorhome with the exception of some cabinets and drawers that may get blocked by a slide. This isn't the case on 5th wheels as I've seen some of those where you can't get to the back with the slides closed.