Hue uses Zigbee so ZHA can control Hue via a Sonoff Zigbee coordinator.
The Hue hub is deliberately hobbled to only control Hue devices.
I’ve several brands of Zigbee bulbs working with ZHA, but find controllable switches better as they sense the switch position, control a normal bulb, and can’t be accidentally turned off.
As with all mesh networks, more devices improve network coverage - Zigbee light bulbs can act as routers to pass messages on. The standard advice is to pair a device in the final location (so it can see neighbours), but worst case, try pairing next to the Sonoff coordinator, then move to the final location.
LED lights often use inefficient circuitry to drop mains (120VAC / 240VAC) to LED voltage (3V3 for control, 3V-60V for LEDs), so all can get hot.