Without a bridge, you must be within Bluetooth range of the opener with your smartphone. This will not usually be the case, e.g. in a block of flats. I don't think the Opener is usable without a bridge.

This intercom is not on the list (from Nuki) of compatible devices.

Gemäss Nuki mi folgenden Kompatibel: ALDUP/40 ef ALDUP/40 ws ALDUP/A ALDUP/G Check unter: https://nuki.io/en/opener/ Compatibility check

Unfortunately, the BPT NC321 is not (yet) listed at https://nuki.io/en/opener/#compatibility. You can still add the BPT NC321 and be informed by email. Or you can also ask Nuki.

Not directly with Hörmann, but you can wire it as any button in parallel to your button in the garage, then it will work without any problems. Provided your garage door opener has one. But I would recommend other solutions, because in a garage you rather want to operate the status as well as open/close/stop. A Nuki opener works, though.

No, the image is not transmitted. You can only control the door opener remotely.

Yes it is compatible with the Koch TC 50 you can check it on the official Nuki website https://nuki.io/en/opener/