Hoping for some help with spatial planning for some furniture in our new home.

Please don't make me do math!

The family room space is 19'L x approx. 15' W (give or take since it opens directly into the kitchen) The yellow circle shows the hall entry into the space that will need some open space and obviously some open walkway between the family room and kitchen. (The red just indicates a different kitchen design so the entry from kitchen to dining room changed..)

I was hoping to do an L-shape sectional or some type of chaise sectional so that it feels cozy and hubby can lounge and not always hide in the basement.

What size sofa and what size rug would you put in this space?

Could I fit like a 107" x 96" ish type sectional? Too much? It's not a small space, but it cannot be up against any walls and needs decent aisle width on both sides and back. I'm OK with it being a large (but still reasonable and not ridiculous) portion of the space. There will be a coffee table, and perhaps one or two chairs depending on how much couch I can fit.. And perhaps eventually some type of bookcase or credenza or something along the brace wall near the hall entrance..

The dining room is 14.5'x12' with a bay window..

What size dining table and rug should go in there? Can I fit an 8 person table? There will eventually be a credenza on one side...

And what type of window dressing do people do on bay windows? It will not be a particularly formal dining room. Should I do roman shades or panels on each side of each window?