I interpreted brutuses answer "paint the inside of the doorway the same color as the first room you enter" as follows: I have a family room on one side of my kitchen and a dining room on the other. Both are painted the same color. As I enter the kitchen, I would paint the inside "doorways" the same color and once you are in the kitchen, that is a different color. You could reverse that and say what about when you come out of the kitchen, but you can't come out of the kitchen without having "first" gone into it, by way of one of the other rooms. The continuity of the color stays in tact. I think that answer also means it will vary by interpretaion and individual opinion of the flow of their space. I also questioned the continued use of white baseboards/trim. The contrast of the white baseboards remind me of the way I learned to color and always outlined in black, to keep my other colors within the lines lol. I decided to use a wood stain that matches the floors. It's time to color outside the lines... :)

Easiest and least expensive? Use channels over the studs, look at EC-8 channel. The channel gets screwed to the drywall the drywall to the channel. Consider use a single layer of 5/8" drywall on the mechanical room side and two 1/2" layers on the theater side. The different thicknesses will help attenuate different frequencies. Both the channel and the drywall are inexpensive. $ Acoustical sealant. Treat the perimeter and any penetrations through the wall; partition studs to adjacent walls, sole plate to floor, electrical boxes, etc. Batt insulation. Roxul sound batts are better than FG batting. But as a stand-alone, cavity batts are lower on the sound-attenuation totem pole than the steps listed above. $ If you want to spend more money, you can use green glue or equivalent when you hang the drywall. $$ You could use mass loaded vinyl. $$$ Just remember that the wall as a whole will only be as strong as it's weakest link. ie, don't splurge on the wall and ignore the ceiling joist bays, etc.

You should be able to remove the intervening wall between the two dormers to create one large dormer and one larger room. Just about anything can be done with enough money. I would consult with a structural engineer or a contractor who has access to and engineer to figure out what will be needed to accomplish your goal.

Help! I'm painting greige in this living room and red in the dining room. There is a soffit that separates the two rooms overhead as well as a painted wood panel on the long wall. Do you think I should paint the underside of the soffit AND the wood panel separating the two rooms both red for continuity, since the dining room wall extends to under the soffit on the other side? Or will that look crazy looking in from the living room? The homeowner is keeping the trim natural wood, so no opportunity to paint the panel a trim color. Thanks in advance for your thoughts!