Will I lose the warranty by flashing an update, rooting or unlocking the device?
This depends on the update. If it is an official update, you are welcome to install it. If you don't know how to do this, you can always contact us.
However, if you try to install a custom rom, or unlock the device, or if the device is too unlocked or too rooted (except for devices that are already unlocked or rooted, such as Xiaomi devices), it's very possible that the manufacturer will refuse the warranty. This must be decided on a case-by-case basis.