Hi Ness and welcome!
Up to you about moving LO to his own room really. I have moved both of mine out of our room at four months but that was a personal choice, SIDS recs are to be in parents room for the first six months. I think it is likely to be easier to work on indpendent sleep with LO in his own room (and you may as well make all the changes together in my view) but you need to make the call about whether you feel comfortable with it.
You can do feeds and winddown where you want
. Winddown can take place in the bedroom, it doesn't have to be downstairs. Just whatever works for you and your family.
Your version of shh pat sounds lovely
. Let us know if we can help more!