I forgot to mention that I travel with an 8 year old boy! Do you mind if he tags along? He would love that pool! Your house is so wonderful, I'm so glad that you took the time to post pictures. I can only imagine the work involved but thank goodness you didn't tear it down! As for the chandelier, yeah, it may not matter what you put there! But, if you want to stay with that cottage cape cod feel consider finding something with more visual weight, and not so many lines. A lantern could be perfect. I don't know if you've ever seen the Currey and Co chandeliers? I love to go to their site just to look at their products, even when i'm not really shopping. This particular chandelier caught my eye for your room. Somethign simple, with some visual weight, although I'm not crazy about the black for your room. But maybe this will spark some ideas... Here is a link that might be useful: Currey and Co chandelier

A formal dining room is going to need a chandelier that hangs fairly low over the table. It’s also an item that is pretty style/taste specific. I’d just put up an attractive flush mount ceiling fixture now and let a future buyer pick a chandelier if they want to use the room that way.

You’re going to need a whole lot of lamps. I hope there are extra outlets. These rooms will be virtually unusable after dark. The ceiling height ensures a dim barely lit space. Unless you can get some wall sconces added, down low. Only there aren’t enough walls. The foyer is the real problem. Especially for a home for 55+. It’s a hazard where you can’t see. We need twice the lumens as young eyes as we age. A single pendant is not going to cut it. I’m not even going to start in on the fact that nothing about it is built as an accessible retirement home. If you ever need a walker or chair, you’re out of luck.

Check RH inspro and go for less Some kind of https://www.homedepot.com/p/3-Light-Rectangular-Metal-Pendant-Light-Fixture-Farmhouse-Hanging-Lighting-with-Steel-Net-Shade-Black-Finish-WBPT-Y019-BK/321395660