It can be good and can be bad. I've found some good deals, and a lot of not so good ones. ultimately its difficult to find windows to fit what you want as far as openings from craigslist. we're doing a whole house remodel/addition. I bought 2 windows and a patio door. Patio door was from a pella dealer who had a special order that was misordered $1800 door for 400 brand new. The windows were arch top casements that someone ordered the wrong size, they were very pricey and cool, I paid 200 each. For normal windows it just doesn't pay, they cost money, butt hey're not that expensive. You're not going to get such a great deal that it pays to compromise the design and you're not going to collect enough matching ones. if you see something you really like at a good cost, buy it, but for normal double hungs and casements... unless you find some really super deals, it doesn't pay.

All the major door manufactures have visualizer softwares. I would definitely start there. You can actually take a picture of your home and test out different options in term of the door selections to get a realistic representation. Provia has a nice visualizer as part of their App. Probably worth a download here and it is free.

Two way draw panels work quite well on a slider. Depending on the fabric, lining and fullness, they should be fairly easy to open and close. There are many hardware options now that have a special lining inside the ring to help the panel "glide" across the pole. Many corded traverse poles look great now......tracks are hidden inside the wood or metal rodding. And of course motorization is one of many ultimate luxury items for a master bedroom and certainly makes moving the panels effortless.

Thanks for the suggestion Mama Goose! What are your thoughts on a single wall oven below the counter? Here I have it next to the fridge which allows for keeping both a larger pantry and the countertop space. Or would it work on the island, closer to the fridge but facing the range? I also followed your prep sink on the island suggestion to move it away from the oven door swing, but I wasn't sure what is best for function: center vs off-center (I'm drawn to symmetry if it wasn't already obvious!). This of course will take convincing DH it's worth the trouble, lol!