I agree one should beware of functionality of RV with slides in at time of purchase. Nevertheless having to fully open your rig to get to the water pump switch could be a deal breaker. But having to open a single slide is not as big deal as many tend to make it.
If you are on the road and need access just open the slide as required. There is no rule /law/ reason you just can't open it up.
Prior to owning my current rig I placed more emphasis on full access as well however opening the fridge slide is no big deal.
As Nike put it Just do it