I’m sorry, I’m not feeling well this morning and as I rely on text to speech I didn’t pick up all the details in your post. But I did want to comment quickly on the two different models of the accessories and also on the minimote.
Once you get to zwave plus devices, you can no longer use the minimote because association has changed significantly in the newer generation.
However, you don’t need it, because a community member has created a very nice software utility which will let you do the associations just through the SmartThings mobile app. It is called the Z wave tweaker, and it is listed in the FAQ on how to create a virtual three-way with the linear/go control switches.
When you’re looking at the two different models of the accessory switch, the one which has a “five” in the model name is Z wave plus version. (Series 500 equals Z wave fifth generation equals “Z wave plus” which is just a fancy marketing name they gave it).
So if you did want to use the minimote method, you need to have the older version of the accessory switch.
Second, when you say you don’t want any hub at all, you have to have a hub when you are using Z wave devices, because it is the hub which establishes the network and assigns the network ID is to each individual device. No hub, no network, so no association as possible. If you do you set up Z wave direct association, the messages don’t have to go through the hub at the time that they are sent, but you still have to have had a hub in order to create the network that each device will send the messages over.
In this forum, that will generally be one of the Samsung smartthings Hub models.
So if you’re going to use zwave or zigbee, you have to have a hub of some kind.
The alternative is to find some Wi-Fi Switch models that allow you to create virtual three ways without traveler wires, but that’s not what most people use with smartthings and I can’t think of one off the top of my head although I’m sure there are some. Most of the Wi-Fi switches will also work with an Amazon echo device once you decide you want to add voice control.
The following FAQ lists the battery operated switches that work with smartthings. But again, you will have to have a hub for most of those.
So basically you need to take a step back and think hard about your “no hub” requirement. If you really want no hub at all, not even a SmartThings hub, you can do it, but you can’t use any of the models that you’ve already listed. Because you can’t use anything that is Zwave. You need to start your research over looking just at Wi-Fi switches. ( or maybe Bluetooth, but that brings up a whole separate set of issues.)
If by chance you already have iOS devices, you might look into apple’s HomeKit. There are many fewer device choices than for smartthings, but it works reliably and there is no hub required. 