"Pentadactyl was once called Vimperator, initially written by Martin Stubenschrott, then developed and maintained by Doug Kearns, Kris Maglione, and several other invaluable contributors. Doug and Kris, the primary Vimperator developers for several years, have left the Vimperator project and now develop and maintain Pentadactyl in its stead."
So it's essentially the successor to Vimperator, or at least a well-maintained fork by the original authors.
noremap <Down> <nop>
noremap <Left> <nop>
noremap <Right> <nop>
I use only 4-5 fingers most of the time and go faster than most touch typists.
After getting comfortable with this setup, I find it is now a pain to drop down to use the arrow keys. This type of setup really helped me 'convert' to a vi way of thinking. I am still learning, but am liking the minimal setup.
I suggest VimGolf as a way to learn new commands, especially how to use them efficiently. It was how I learned to use "w" and "b", as well as macros.
The second was once my job was automated, I got to play a bit of nethack. A text based game that uses that style of navigation did help a bit.
:inoremap <Space> <Space><C-g>u