tente adicionar isso ao seu .vimrc
autocmd BufReadPost * startinsert!
De: h usr_40.3
The general form of the :autocmd command is as follows: >
:autocmd [group] {events} {file_pattern} [nested] {command}
De - link
:star[tinsert][!]
Start Insert mode just after executing this command.
Works like typing "i" in Normal mode. When the ! is included it works like "A", append to the line. Otherwise insertion starts at the cursor position.