Overall I'm not a fan of these additional spins of linux. System76 does this too with PopOS.
Our experiences are nearly polar opposite and the only difference I can detect is the OS.
I can say that the bluetooth works as expected (currently using a mouse). There is a bit of configuration that had to be done to get a Plantronics headset to work with LinPhone for my VoIP line, but that really isn't something I'd expect to work seamlessly in my environment.
For the headphone jack mine clearly works as expected. Though I haven't tried Apple's earbuds which may be a more common test item. I'm using Shure earbuds and the connections are flipped.
That load is high. I'm averaging 0.71. Maybe you're doing something more intense than I am, but generally I have a Windows VM (MS Office open) and Firefox/Slack/WebStorm running.