The installation guide provided for gentoo is detailed and comprehensive, however it is also difficult to navigate for newcomers to the distribution. There is no clear deliniation of what steps are optional and what you can and can not skip. Also, I encountered a few bugs when going through the install procedure, but there was nothing in the install docs on troubleshooting. The guide needs to be cleaned up a little bit, reformatted (separate out sections more than they are... the colored text boxes for notes and hints is an excellent starting place) and in some cases dumbed-down (perhaps a simpler quickstart guide of some form could be useful here). Even though this is meant to be a user document, it still reads too much like a technical document. The simpler and easier to get through the install doc is, the better Reproducible: Always Steps to Reproduce: 1. 2. 3.
I don't agree with several items you describe. First of all, optional items are clearly stated as optional from my pov. Bugs during the installation should be reported on bugs.gentoo.org or asked on #gentoo, there shouldn't be bugs in the document, but we can't fix them if we don't know what bugs you have encountered. The reformatting is a matter of rewriting the stylesheet, something that will he happening if GLEP 13 (see http://www.gentoo.org/proj/en/glep) gets approved. I'll mark this as LATER
The handbook is now official; this bug is now closed.