Modify Write screen to…

Hi all. I have a lot of back post I’m doing in creating an archive of sorts. Every post I change the date and would like to change the “publish immediately” which has the edit link next to it to be a permanent display of the date of the post. I don’t mind the extra clutter.

Would this be hard to modify one of the files? or am I going to create a mess and bigger issues? Thanks for any help.