Hi,
For the first issue, it’s hard to say, but I would presume a plugin or your theme is adding inline scripts somewhere which is being treated incorrectly (possibly the same as in item number two, given that it’s the same warning?)
For the second issue, you will need to reach out to Elementor, as it seems one or more of their JavaScript files are using outdated code which will stop working soon.
We can not help directly with fixing these issues though, you need to reach out to the individuals involved, in this case the plugin authors of Elementor at the very least.
For your final issue, Quirks Mode, I’m going to copy my reply from elsewhere, as it’s a bit detailed;
Your browser is currently in what is called Quirks Mode, most likely, in your address bar, you have an icon of a blue document that’s “broken”, clicking on it should let you select the quirks mode status of your site.
If you do not have an option to disable quirks mode, it may be automatically enabled by your browser because of old code on the page you are viewing, it’s unfortuately not possible to pinpoint the exact reason for that via a screenshot though, but we recommend following the regular troubleshooting steps at https://www.ads-software.com/support/topic/read-this-first-wordpress-5-5-master-list/, just turn on the Enable jQuery Migrate Helper plugin first to see when the problem reappears.
Quirks Mode is a browser thing, it’s really not something that can be directed at any one plugin without doing the manual task as mentioned above, this is because jQuery can only detect if quirks mode is active in the browser, not what caused the browser to make the change.
