I have touched on this before but seeking clarification if this is the best way to avoid files being overwritten if you need to create extra pages after you have already exported and changed forms with CSS.

1. Create new page. Export contents to desktop but name it differently. Take the new page and all the
.css and javascript files over to the original and copy them in ----- Will this work given you have not changed any other files other than the new page so css and javascript need to replace existing ones but the only additions to these would be anything you did on the new page

2. Create new page. Before exporting change all the files you have to added .css to by changing there name to say index1.html etc. When copied delete all the new files except your new page and change the names you changed back to the original.

Are these feasible for avoiding data loss. Yes I know it is better to have all your files ready before exporting but we don't live in a perfect world.

I make a custom.css and place the link to in the head of the page in RLM. I then keep this style sheet where it doesn't get overwritten by the export.

Yes I agree with this.

Sorry I meant to add changed the index.html etc files HTML code not CSS. i.e. adding sliders, links social media etc