Welcome to openHAB!
Theres’s a binding for Tuya devices, but you have to add it from a third-party marketplace. With the Tuya binding, you don’t need to worry about flashing Tasmota, which has gotten harder to do over the past few years.
I think this would also work with Tuya radiator valves, but I’m not certain since I don’t have any.
Battery-powered Tuya WiFi devices will be offline most of the time to conserve power, then hop onto WiFi to report or check in daily. So, there can be some latency which may or may not bother you.
If you replace your existing sensors, I’m really impressed with IKEA’s new PARASOLL contact sensors. I’m of the opinion that Zigbee is the best choice for Battery-powered sensors at this time.
You can also get Zigbee radiator valves from Tuya.
Don’t get an Aqara hub. Many Aqara devices are Zigbee, and will theoretically work with a Zigbee controller…but they’re sometimes difficult. I struggled with their contact sensors and returned them. Others have had more luck.
Personally, I’d just mount motion sensors under your bed. The PARASOLL link I gave above also talks about VALLHORN motion sensors that would do just fine. This also has the benefit of requiring a heat signature, so dropping something on the floor won’t trigger your lights.