crum, most of the install hacks you are talking about are no longer valid, nor is the old documentation.
Things change, and hardware requirements are creeping up. Install from optical disc, or USB drive created using dd, are the only recommended install techniques.
The "install from iso" option is mainly for devs who do a lot of test installs. If it works for you, good. Just remember to prepare your hard drive in advance and copy a VL ISO to the root (very top level, not in a folder) of a partition that you do not intend to use during the installation.