You can leave the dimension alone and fix it with the ModelOffset property as well. That way you won't be able to place blocks inside your door. Good thing to know is that the default model offset (when the property is not there) is "0,0.5,0". You need to add 0.5 for the first or last offset if the dimension is 2 (or maybe even all even dimensions). So for this particular door it's "0.5,0.5,0". For the spinning door it was "0.5,0.5,0.5".
That is some fantastic modelling. Are they your own work or existing assets? Either way, the only thing that could possible be improved is to have the water surface to have some animated waviness because now it really feels like a mirror.