Actually, any key that you don't use as a hintkey can still be used to narrow down the hints. I use lowercase hint keys, and I can hold shift and type the link text (as the matching is case-insensitive, but the labels are not). It works very well.
For aesthetic reasons I like to render the hint labels in uppercase. It can be done by adding text-transform: uppercase; to the Hint selector with :highlight
where? the "command...." entries? those are basically javascript bookmarklets that are typically installed in your bookmarklets bar, but have now been assigned their own command. e.g., just type
It is - the way you enter passthrough mode for domains in Vimium vs. passkeys for Pentadactyl is what makes the difference for me. Being able to still use the plugin when I'd like to and when I don't is perfect.
Also - if you'd like lettered keys, try setting the following option in your .pentadactylrc:
set hintkeys='ASDFGHJLK;"
You'll lose the ability to type the hints' text to hit them.