There is something fundamentally wrong with LO paragraph styles. Its built-in styles, and the ones I create, specify a font face, size, and formatting. But if I convert one style to another (say, from Default Text to Heading 1), the font and formatting do not change. I am forced to change them manually to what the style already specifies. It is important that all the attributes specified in a style come into play when you reformat text from one style to another.
I am using the latest version of LO Writer under 64-bit Linux Mint 17 Mate on a PC.