Need help 'designing' a home network solution for my house

What is your budget and level of networking knowledge?

I think your proposed design looks good. Now realize there are many ways to do what you want, and everyone has different hardware they like. So you may get a bunch of different answers to this question, but here is what I would do (in fact many of the things I propose I actually have done in my home network).
I would put most of your money into your primary WAP. You have many devices that are wireless and this will be the bottleneck in your design. Most consumer AP’s will not even connect more than 20 devices and most consumer AP’s will start coughing when you have just 4 or 5 heavy devices in use. So I would go with a Pro level AP. One of the vendors I use and am very familiar with is Ubiquiti. Thus for the AP I would recommend either the UAP-AC ($300), or the UAP-Pro ($210). Both are simultaneous dual band 2.5ghz and 5ghz, but the Pro is the older N technology and does not support AC (but still a very good AP). Another nice thing about these AP’s is that they allow for a separate visitor SSID and network without having to use multiple VLANs (though they do support multiple VLANs and multiple SSID’s).
Now for the router. Since you have a little bit of networking knowledge I would recommend the Ubiquiti Edgerouter Lite. It is also Pro Level gear but has a very good price ($100). It is not the easiest thing to set up (though with the newest OS it has wizards that will do most of the setup for you), but it is extremely fast and rock solid. It should go months if not years without a reboot. Also it can do almost anything which will give you options in the future, like creating VLANs, setting up a VPN server so you can access your network while away, etc.
One thing I did not ask is what speed internet connection do you have? If you use the Edgerouter Lite it does not really matter as it can route at near gigabit speeds. But if you decide to go with a consumer router you will need to make sure it can route at least as fast as your internet connection.
Okay for your switch. For home use I really like TP-Link switches. I have had extremely good luck with them (both managed and unmanaged) and the price can’t be beat. For your setup I would recommend a smart (managed) switch. At first you can use it just like a dumb switch (plug it in and go). But it has the ability to do VLAN’s, port aggregation, and has graphs and counters so you can see port usage. It also has diagnostic tools built in to help you identify where there might be a problem on your network. It looks like you will want at least a 16 Port switch. So a TP-link TL-SG2216 16 port switch would be $140. If you wanted to go with a few more ports for expansion, the 24 port in that series is the TL-SG2424 for $170. Those switches are gigabit switches.
Now for the second WAP could you just use your Dlink DIR-632A? I did notice it only had 10/100 ports on the back and not Gigabit. Did not know if you really need Gigabit speeds there. If you need Gigabit wired ports there, but the Dir-632A is fine for wireless, I would just put in a small, unmanaged Gigabit switch, like a TP-Link TL-SG105 ($30).
Anyway for the AC WAP, Router and 16Port switch it would be about $540. You could save money by not getting a managed switch, it’s up to you.