It would be possible to put a play corner in the first two drawings but not in alternative 2. I would recommend a corner of storage furniture to corral the toys. I am usually a fan of built-ins but not in this case because eventually the kids will outgrow their toys and you won't need that storage there anymore. The built-in exception would be a window seat under one of those windows on the plans. Some of the storage could be cabinets or bookshelves for bins or toys underneath a window seat. I'm not a fan for toy box style storage because they either become a black hole or the kids throw everything out of them looking for what they want and then do't put the rest of it back. As for the kitchen placement, near to the deck would be best in you like to eat outdoors on the deck or entertain on the deck. We entertain a lot and the kitchen is on the other side of the house from the patio. It's a real pain and a big part of my design brief for the architect was for the kitchen to be next to the patio. I even wanted a pass-through window from the kitchen sink to the patio for ease of clean up but unfortunately I wasn't able to work that out.

Often good re-decorating requires taking some elements away, but you are asking for a feel of luxury, so you need to carefully add elements. If you have enough space and budget, then consider continuing the built-in to the other side of the fire place, and painting all of it to match. That will anchor the fireplace as the focal point of the room. Fabric can really add a sense of luxury so you could raise the curtain rods and add longer drapes on either side of the windows, with a filler spanning in between, not a swag, but something like you'll see as an example on the the first picture that Beverly posted. Original art says "luxe" and it looks like you have space for a great and sizable piece of art on the wall adjacent to the sideboard across from the dining room. Larger accessories absolutely, and some that are taller. They don't have to be expensive, but they should be things you really enjoy looking at and that you find delightful, or even amusing. Garage sales and flea market are gold mines. Then look carefully at the 2nd pic from Beverly and you'll get and idea on how to do a collection of smaller items to make a bolder statement (collections are 3 or more items.) The key to unifying is color. You've done a good job with your neutrals, add a couple of more luxurious throws in that palette and a few pillows. It looks like you enjoy blues so add that to the mix as well and a pop of black here and there and you should be well on your way.

For the bar stools I like the grey/white better. LOVE the table. Not sure about the black leather chairs, they seem a bit dark. Not sure these would go well together. Your dining room choices are very sleek and modern while the bar stools are more beach or traditional.

I guess I would start with the kichen being complete and that needs to done after the same flooring is installed everywhere I really am having some difficulty relating the pictures to the floor plan. In the pictures where is the mud room?