(Click to enlarge)

You can disable web standards checking in configuration. It might be under accessibility if I recall correctly.

With that being said, using attach messages for the errors is not the best. I'll see if I can tidy them up a bit. Mediafeeder should be added into the exceptions.

Not likely I'll get to the tidying up before 11.0, but I'll add for a future minor release.

Deleted the addon, everything I do it informs me of some nonsense.

That's not a constructive way to solve the issues. It's your choice if you want to get rid of it, but health check has a lot of valuable tools to help inform you of possible (and sometimes urgent) issues with your site. Plus, I'd like to fix the issues you're having, which I cannot do if you simply remove it.

I agree, but I never used the Health Check in v10 and I doubt I will be using it in v11. I've reported the errors I've seen (emoticons, curl-error-7, page appears broken, spelling, web standards). Sick of seeing them now. Trying to work out how to get my custom media player to work in v11. It's certainly not as straightforward as in v10.

Another one: Lines that are just white-space (:home) <-- So what?