So unlocking bootloader and using it as daily driver should be enough for now right?
There won't be data loss when we do get magisk?
No, data will be lost only once, after unlocking the bootloader, so I suggest the first thing you should do when getting the phone is unlocking the bootloader.
A quick guide would be:
1. Go to Settings / About phone and tap on "Build number" 7 times.
2. Go to Settings / System / Developer options and turn on OEM Unlocking and USB Debugging.
3. Connect the phone to your computer, open a terminal and type 'adb reboot bootloader' (assuming you are running cmd from the adb folder, or have bash profile setup accordingly).
4. Once the device is in Fastboot menu, type 'fastboot oem unlock', this will reset your phone to factory settings.
5. Reboot and then set up your device accordingly as you won't need to do this again later.
6. Download Magisk .zip file on your device from here:
https://xdaforums.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445
Once the correct TWRP for OP7 is released you can do the following steps:
7. Download the correct TWRP .img file to your computer and the correct .zip file to your device from here:
https://twrp.me/Devices/OnePlus/
8. Connect the phone to your computer, open a terminal and type 'adb reboot bootloader'.
9. Once the device is in Fastboot mode open a terminal and type 'fastboot boot path_to_recovery_file_that_you_downloaded_at_step_6.img'.
10. Once the device is in Recovery mode tap on 'Install' and select the TWRP .zip file downloaded at step 7 and when it's finished reboot to 'Recovery' again.
11. Once the device is in Recovery mode again tap on 'Install' and select the Magisk .zip file downloaded at step 6 and, when it's finished, wipe cache and reboot to 'System'.
That's it.