The rooting issue has been fixed, you can now deativate root after flashing LineageOS. There are also apps which hide the fact that you unlocked your bootloader

The rooting issue has been fixed, you can now deativate root after flashing LineageOS. There are also apps which hide the fact that you unlocked your bootloader. As for the updates: This depends on the device. Check the list of supported devices and you'll see that there are quite a few with weekly updates.