I have a couple of questions about the process of returning the finished layout to the customer, can you help me figure it out?

Question

Freelance

Hello) there are a couple of questions that bother me and do not allow me to calmly enter freelancing)
1) so that later it would be easier to implement the site on any cms. Should text elements be wrapped in div or p tags?
2) it is better to write paths to images in html or css, so that later it would be easier for the customer to change them.
3) Is it better to use JQuery or pure Js? Those. Does it somehow affect the page load speed and something else?
4) I am using the gulp builder. Of course, there are special plugins there, a la carousels, animations and all that. Accordingly, when I throw off a ready-made folder with all the data for the project + gulpfile.js , how the client will connect all these plugins to the hosting. Well, I'm interested in the process itself. Plugins are not included in the head.
4) maybe there are kind people who are ready to share their social networks or tg in order to answer my questions in the future?