Converting PDF to EPUB without wrecking the layout

Honestly you mostly can't, and it's not the converter's fault. A PDF is a fixed page; an EPUB reflows text to the screen. Every tool has to guess where paragraphs, headers and page numbers are, and on anything with columns or images it guesses wrong. Calibre is the best free shot. Before converting, in the PDF input options, try the line un-wrap setting and the header/footer removal, it cleans up most of the broken lines. If you have the original Word or Google Doc though, convert from that instead. Night and day difference. And for something like a cookbook or a manual where the layout IS the content, I'd just keep the PDF.