Questions about Philips Hue White BT

Almost all Hue lights are Bluetooth enabled. However, you need the Hue Bridge because Apple HomeKit, at least as far as I know, does not communicate via Bluetooth but via the network. With the bridge, you integrate them into the network and can thus add them to Apple HomeKit and also control them via it.

Philips Hue forms a mesh network in operation with the bridge, according to the ZigBee standard. So yes, each lamp extends the network, but the bridge is a prerequisite.

You can programme the dimming variants through the app. And the dimming is not as fast/precise/sensitive as e.g. a screen brightness control in the mobile phone.

The Philips Hue White & Color Ambiance BT has 5.70W and can also light up in colour, unlike the Hue White.

They don't need a transformer, just "normal" 220V - 240V directly from the line without any other frippery.

yes, it is possible with the hue bridge. remote access is also possible.