Re: "." is broke
The "." key, which the vimeu docs correcty say is the single most useful command in vi/vim, does not work right.
For instance, position the cursor somewhere, type '4s' and type the characters you want to substitute.
Hit escape, navigate elsewhere, and hit '.'.
All it does is delete 4 characters, but does not do the previous substitution, as it should (check it in vim).