[itimpi]

Calibre is not an editing tool - it is intended as an ebook library magement tool, and it provides conversion capability between different formats. It will allow you edit things like metadata associated with books, but not the actual text of books.

As to why you cannot see any text in Sigil, I have no idea. it has always worked fine for me. The ability to work in WYSWIG mode for most editing, and then switching to Code view (HTML mode) for fine tuning should give you all the control that you want. Are you perhaps only looking at the first HTML file in the Epub (an ePub book is always split into multiple HTML files as most reader devices cannot handle large ones), and that is why you are not seeing the text?

If you have Sigil specific questions they are probably best asked in the Sigil forum here on Mobileread.