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.

Unless you have some special situation that we don't know about, the basics are that you need a table and chairs in the dining area. How many people do you want to seat? Do you need more storage in that room too? Benches are not as comfortable as chairs, and don't fit well in the room with your windows and baseboard heating units. Are there children or adults only? For the living room, a sofa and 2 chairs would fit well. How many people do you want to seat at one time? 2 chairs are better than a love seat, comfort-wise. It looks like the side near the front door is open - what does it open to? Will there be a TV in this room? That will make a big difference in furniture arrangement since there seems to be only one wall it can go on. When you send us the room dimensions with door and window openings we can give you an idea of sizes.

Sorry so many comments, internet slow and won't take a lot of pics at once. Walls Bittersweet stem, accent wall as above. I'd paint the door the wall color since you don't have trim around it. It looks unfinished in these pics. not sure these are the right colors but they give you the idea.

Since it is all so open, I would paint the same color in the kitchen, dining and living. Maybe the creamy white of your dining chairs would work throughout. If you don't want to paint the kitchen, you could bring that same color into the dining/living. Or you could take another shade from that same color strip/card and bring that into the living/dining. Other improvements: your rugs are too small, and so are your lamps. Your dining light is dated and your art is dissonant and not hung correctly. The coffee table is too large and heavy, and I would match drapes to the wall color once you figure that out. I do like your red cabinet and blue cache-pot! Have you thought about installing drown molding? How high are your walls? Here's a creamy white on walls (Navajo White) and brighter on trim (White Dove) so you can get the idea, even though this is not the style of your home.