Hi,
Sadly, even if Minio is probably better than others (eg BackBlaze), they can suffer from various issues. There's a reason why we only provide official pro support on AWS.
Would it be possible to test another provider to double check it's not XO related?
Hi,
It's not relevant for our most critical users (ie paid customers), because they don't want to have a complex matrix. They all come from VMware and they need something simple to explain.
If you are a home labber, you can just check xcp-ng.org website and https://docs.xen-orchestra.com/installation, that's enough 
Can you do a lspci in the Dom0? I'm not sure the audio device is an adressable device (unlike Nvidia cards for example)
Each month we release new features, so it's hard to tell, it depends on which feature you are expecting exactly
Upstream inclusion is ultra recent, but you can always add drivers yourself (still requiring a relatively recent kernel IIRC). Anyway, we have the hardware and it will be in the roadmap at least to explore
Yes but in order to see the VF I need a working driver in the Dom0 first 
Probably a lot easier with a more recent kernel in XCP-ng 9.0
