Changing System wide dialogue boxes

I have been using the Mac since 7.3.3 so I know for the most part what I am doing. OSX likes to add these dialogue boxes that annoy me in that I have to reach for the mouse...so I would like to change them

1. the dialogue that you get when you change the .### extension on a file
I can't remember the rest but is there a central preference file I can mod so that "add" is the default instead of "don't add" ?

This way I can alter the onces I was going to measure but forgot :confused:

thanks in advance

m