Shall there be a codelock on it?

well the plugin page says so.
"This plugin automatically removes one codelock for every door, a code lock must be in the inventory for it to work"

it it possible to have /autolocks lock on as a default maybe? 

just a quick question, you dont know how to read? plugin page says it does.

just a quick answer - To use it i have to first do /codelock pin xxxx then /codelock lock and then place door....

well first lock is required to do that with, then the following locks will keep getting autolocked on placement. It does for me