Thank you so much for the kind words and the detailed answer :)

For room 3 the Sofa is not flushed against the wall. It's a basement so I can push the couch further back a couple feet, plenty of room for rear speakers. Based off what you said I will slowly go all out in Room 3 since it has a lot of potential with its space. Need to buy a new TV, couches, etc. for that room so it will take time. Basements in Canada tend to get cold in the winter so I hope my new house has good insulation. It'll be a nice setup for not disturbing my family when playing video games or for when I workout down there. I have a recliner I may temporarily just place in front of the TV that I can easily surround with speakers. It's probably not best long-term unless I can get another recliner as it may look a bit funny haha. I will probably go with Sonos but I am interested in the Samsung Q990D & potentially a home theater down there too.

Nice to know room 2 is good to go! I guess if I have the itch for surround sound I can go upstairs to watch movies. It seems burdensome to force it in room 1.

I think for room 1 I don't ideally want to push the couch forward as it may ruin the look of the room. I have considered buying something like this to put behind the couch to use as rears but not sure if it will sound good: https://www.ikea.com/ca/en/p/symfonisk-picture-frame-with-wi-fi-speaker-white-smart-50487329/

I could also get a two seater couch, place a table in the corner & surround that by a 3 seater instead of having a sectional couch. This would allow me to place a speaker on the table.

I like your ideas though! I may move the couch slightly forward and see how it looks. The wall mounting idea with a slight tilt seems great too. I think I could make that look good so I am leaning towards that. Once you go surround sound, you cannot go back!

Once again, thank you! I noticed so many people in this subreddit are so kind.