Re: 4 way switch arrangement
At my home, the lights for the staircase are contolled by a 3-way dimmer at the bottom of the stairs and a 3-way switch toggle at the top. I see no reason that a third switch of the 4-way variety could not be added, if there were a need. If you can build a circuit with a pair of 3-way switches and one or more 4-way switches, it should not matter that one of the 3-way switches is a dimmer.