Can I stop using auto ads and still use Amp and Site Kit?

If you prefer to use WP Quads on your site and place single ad units on your AMP URLs as opposed to Auto ads that’s no problem.

Will I be able to still use your AMP plugin if I reject the auto ads?

Yes, ads are not required to use the AMP plugin. Many AMP users don’t have ads on their site.

The auto ads, for instance, entirely block my website content when the vignette ads appear. I’m shocked that Google would want to do that when they constantly say that content is key.

You can disable Vignette ads if preferred from within your Auto ads options at AdSense level. More information below:
https://support.google.com/adsense/answer/9305577?hl=en&ref_topic=9261304

You may wish to confirm with the AdSense Help Center that these ad format options also apply to AMP URLs, not all Auto ads settings do.

Briefly, Can I stop using auto ads and still use Amp and Site Kit?

Yes, you don’t need to use Auto ads on your site to use AMP and Site Kit.

why do you mark things resolved when the person with the question needs more information?

I have not seen the auto ads settings that you posted. I looked for settings, and found none. I’m not sure why they would be so hard to find.

Also, on my very long pages auto ads were doing two ads. I don’t really understand how they are configured…

And, they seem to only show one ad… in different places. The ads also seem to be something Google is pushing, rather than something related to what the person who is using the page had been searching for using Google search…