Updates are checked for everyday. There is no way to disable the update checker
If an update is available, it will show update is available. There is no way to disable this either.
You can disable apps from automatically updating. This is what the "Disable automatic updates" button does.
I've not noticed anything in the last few days, but in the last say month or so I have noticed outages a handful of times (whereas previous to that I'd never seen any), and yeah I think load related (have a vague memory that it told me as much and said to try back soon)
@humptydumpty The site you are trying to embed needs to "allow" embedding. These days many sites prevent embedding by setting X-Frame-Options or CSP headers. The browser reads these headers and will blocked the embedding. Did you see the browser console? Usually, it will say that frame loading got blocked.