Guess by using the AT command for changing the IMEI: AT+EGMR=1,7,"123456789101213"
Anyone can make a lot of claims in a forum, so I would at least answer this question with “maybe”. As far as I know, there was no independent testing of the devices - so you have to believe the (advertising) promises here.
The same with this question. I doubt there is any super-secret tracking software installed - also because the GL.iNET team already has their hands full dealing with existing bugs (and other devices).
But: closed source firmware means it’s possible. Also because parts of the firmware are really “closed” and you can’t look inside - like the driver, for example.
There is no proxy included, so this doesn’t matter.
Guess no, if you don’t use GoodCloud. But: Closed Firmware, so maybe.
You can be happy if you can read your text messages yourself - depending on which country you are in and whether the text message contains special characters, this only works to a limited extent.
China-located company with branch offices in US.
This may not necessarily mean that the state is involved. But I wouldn’t place any bets on it either, no matter what anyone tells me. Both states are known to have measures in place to enforce their will and you are NOT allowed to talk about it.