The justified alignment looks sub-par in places, like in the middle of the first paragraph of the example pages.
Flush left alignment normally is the better option, if you don't have a hyphenation engine.
It really baffles me that some formatting engines require that soft-hyphens be pre-inserted. For eBooks, particularly. Apparently Kindle supports hyphenation only if the book has explicit soft-hyphens. Google Books doesn't seem to support it at all. Meanwhile, FBReader does a perfect job of hyphenating arbitrary ePubs. TeX has done it right since what, 1983?
Yes, hyphenation is language-specific, but if your application is laying out blocks of text, a set of hyphenation tables is a basic part of language support.
Browser inserted Soft-Hyphens could fix this, but since they are language dependent browser support is spotty: https://developer.mozilla.org/en/docs/Web/CSS/hyphens#Sugges...
By itself most browsers can break soft-hyphens pretty reliable, but they have to be generated first: See https://github.com/mnater/Hyphenator or https://github.com/bramstein/hypher