There is no difference in the specifications, they are simply two different regional codes assigned by Logitech. But it is exactly the same mouse with the same functions.

Since it is a Lightspeed dongle, the mouse cannot be paired with a Unify. (I found this info on the Logitech Support FAQ). What I don't know for sure is whether the mouse can be paired with the dongle of a wireless keyboard that also uses Lightspeed, e.g. the G915. Unfortunately, the support page for the G915 is incomplete and I couldn't find any further information about it.

Yes, the mouse comes with a USB receiver. I don't think this receiver is compatible with a keyboard. I use a wired gaming keyboard myself.

Yes, you can hear it. Compared to my Razer Deathadder V2, the click is louder, crisper and somewhat brighter in sound.

This depends on the operating system. For example, Windows 10 usually has a "registry key" for this: https://superuser.com/questions/310681/inverting-direction-of-mouse-scroll-wheel

I recommend writing to Logitech Support. In my experience, it's one of the best customer support services around and extremely accommodating. If that doesn't help, you might be able to find a replacement on ebay, ricardo, etc.

Hello Svenup146! Even though I use the mouse stationary on a mouse pad, I briefly tried it out for you on a desk pad and a glass table. It worked absolutely flawlessly on the textile mouse pad and the plastic desk pad. On the glass table it also worked, but occasionally showed stutters or jumps when moving. So in my experience, it works on glass in a pinch, but I wouldn't want to use it on glass (unlike the MX Anywhere 2S, for example). I hope I was able to help you a little bit and send you my best regards.

The mouse is operated with a battery :)

tends not to, no (I have several MX800 mice, which are not compatible with each other (with the respective other USB Bluetooth receivers).

Certainly not suitable for gaming on a glass surface, as an optical sensor is built in. This works best on a good mousepad. For gaming on a glass surface, I would go with a laser sensor, although an optical sensor on a suitable mousepad is certainly the better choice.

No Bluetooth available, the nano receiver must be used for the connection.

The mouse has a normal hard surface.

Yes.

A normal AA battery is used. Whether you want to use a disposable battery or a rechargeable battery is up to you.