Newb to Divi 5 w/AI

Hi there -- I've built many Divi WordPress sites.. about 5-10 years ago.

With all these new features, I'm hoping I can still find my way. As a seasoned front-end developer (CSS, etc.) and designer, I know my way around theming. But I always found Divi to be a nice shorrtcut to cut out the cruft and speed up development.

However, I'm used to the backend editor layout with drag and drop sections, and I've never used live preview drag and drop or visual builder or AI (though it looks impressive, so I subscribed). Will I be lost in the "new" 2025 version of Divi with all the changes?

Are there any plugins you find essential to use in tandem with Divi?

Bonus question -- Is Divi responsive? I can't seem to get a clear answer on whether or not the current version is (for mobile, etc.).

Second bonus question -- How many folks make a child theme and what are the advantages?