I feel your pain, but consolidating topics is tricky. A lot of the conversations span months or even years, and the people involved come and go. The best-managed topics are when one person (often a binding developer) maintains an ongoing thread to discuss it.
This is compounded by people not bothering to search the community before posting anew. So, I commend you for wanting to catch up before posting questions that have been asked.
With all this in mind, don’t fear to ask questions that have been asked before. All that we ask is for people to show that they’ve made a reasonable effort. So, make it clear that you’ve looked through the documentation and tried a few different searches, and give more detail rather than less.
Now, Tuya is particularly tricky, because there are multiple ways to tackle it. Moreover, since there’s no binding at this time, there’s no documentation that collects all of the information into one place. I’m hopeful that a developer will eventually take it on, but that’s the nature of volunteerism.
Flashing Tasmota was a popular way of gaining direct control over Tuya devices, as you could often do it over WiFi with Tuya-convert. However, Tuya started releasing firmware in 2019 that prevents over-the-air flashing, and in 2020 started using non-ESP8266 chips that aren’t compatible with Tasmota at all.
If your older Tuyas haven’t had firmware updates then you might be able to flash them over the air, but it’ll probably be a mixed bag. You can also open up your devices and try to flash them over USB, but that’s more challenging. I tried it on one device, but then I remembered that I hate soldering.
You’re probably better off trying one of the other methods that goes through Tuya’s cloud, since it will cover all of your stuff in one go. Whatever the case, you’ll also need to figure out how MQTT works.
Here’s a recent tutorial that should be generally applicable for Tuya devices. I haven’t tried it, but I bookmarked it in case I ever decide to try it with my one Tuya device that couldn’t be flashed with Tasmota.
Cheers!