Hi. USB supplies only 5 volts, so using a bus-powered audio interface is absolutely nothing to worry about on a desktop computer. If you had a laptop, it would drain the battery only slightly faster than not using it.

I would keep the USB cord at 12 feet or less.

I know what you've read about Focusrite drivers. I have used six Focusrite units; still have two in service (one on my production machine, one on my backup). I have had no problem with the hardware. Most of the complaints are about the software being confusing on how to set up inputs and outputs. On that, the comments are right. But once you figure it out, they work fine.

I'm not familiar with that model MOTU, but in general, there isn't any semi-pro hardware out there with a better reputation. The unit you have in the link has really nice meters. I like that it uses TRS balanced I/O. No digital connections, but that would be unusual in this level of an interface.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.