Hello,

the notice you are getting is coming from the Migrate library and usually is visible when libraries are not minified.

It actually tells you that one of the scripts on the page contains a jQuery deprecated piece of code. Migrate, alongside jQuery (versions over 1.9), fixes issues like this on top of warning you about them.

If you are not the developer of the script that causes that message, you can just ignore it as long as you have Migrate and jQuery loaded on your page.

Just use the option to minify the libraries (one of the last basic options in the jQuery Easy plugin) and the warning will be gone and your page will load faster.

Well, it depends on what versions were initially loaded on your site.
I cannot really tell you what is best for your site without seeing it.
Check the source code of your page, 'click' on the jQuery libraries you can see on the page (before the jQuery Easy is enabled). Usually you can find the version used at the beginning of the jQuery .js file.
Take the highest version used and plug than in jQuery Easy.
Do not use jQuery UI if you don't have it on the page before enabling the plugin.
Do not select the 'base' theme, it is not available for the latest versions of jQuery UI anymore.

Yes, just jquery.min.js