If possible, try to backup your current firmware using the tool before flashing a new one.
A: No. Even though they share the S905X3 chip, the PCB layout, voltage regulators, and peripheral drivers are different. You will brick your device. X96 Mate Firmware
This happens often with Custom ROMs. Netflix requires specific DRM (Digital Rights Management) keys. If you flash a generic firmware, you lose the certification for HD playback. You may need to use a mouse toggle and download the mobile version of Netflix from APKMirror, but the interface won't be TV-friendly. If possible, try to backup your current firmware
If your box won’t start, a flash is often the only fix. the PCB layout
Wait for the progress bar to reach 100% and say "Burn Success." Post-Flash: First Boot