As of Emacs 20.3, there is indeed a
repeat command (C-x z)
that repeats the last command. If you preface it with a prefix
argument, the prefix arg is applied to the command.
You can also type C-x <ESC> <ESC>
repeat-complex-command) to reinvoke commands that used the
minibuffer to get arguments. In
repeat-complex-command you can
type M-p and M-n (and also up-arrow and down-arrow, if your
keyboard has these keys) to scan through all the different complex
commands you've typed.
To repeat a set of commands, use keyboard macros. Use C-x ( and C-x ) to make a keyboard macro that invokes the command and then type C-x e. See Keyboard Macros.
If you're really desperate for the
. command in
redoes the last insertion/deletion, use VIPER, a
mode which comes with Emacs, and which appears to support it.