Can corruption happen by powering off the computer (not properly shutting it down) during balance or scrub of a btrfs volume?

It's pretty good. Even better than the raspberry pi 4 considering its performance and comically low power draw (It doesn't go over the 2W mark even with both cpu and gpu at 100%.). Other than that, it's perfectly usable, despise its lack of (out of the box) support.

They're objectively better than the Raspberry Pi in every way and are much more standard ARM devices than the weird boot process of the Raspberry Pi, so generally speaking, more OSes just work.

My Orange Pi 5 actually supports an open source EDK2 port so it can run any Aarch64 operating system that supports UEFI and ACPI or Device Tree which means almost every Linux distro, all the BSDs, Windows, and even more exotic and up and coming options.

I actually bought it to test my own OS development project specifically because it's one of the few ARM boards that supports the common boot and firmware standards.

On the Raspberry Pi 5 which I also have if you want to use anything other than their own officially supported Linux distributions (so far only Pi OS and Ubuntu) then you have to modify your kernel or bootloader to work with its wacky boot ROM, lack of UEFI or U-Boot, and somewhat non-standard Device Tree along with tons of undocumented peripherals.

Oh, and the Orange Pi has twice the number of cores. The RPi 5 has four Cortex A76 cores while the Orange has four Cortex A76 cores and four Cortex A55 cores in a big.LITTLE configuration.

Honestly, any of the Rockchip RK3588 or RK3588S boards are way better than a Raspberry Pi. At this point, the only thing Raspberry Pi has going for it over its major competitors is the fact that the brand itself isn't Chinese (although many of the boards are made in China).

Basically all of them