As for your questions about an mnl file, I use them to load our files at startup and it works great. If you use custom menus then all you have to do is name the mnl file the same name as your custom menu file and it will load if it's in one of your support paths.
Here is an excerpt from our mnl file:
Code:
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\deloach_utilities_acad.lsp" '(princ))
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\room_tools.lsp" '(princ))
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\30x42.lsp" '(princ))
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\att.lsp" '(princ))
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\blank.lsp" '(princ))
(load "Y:\\AutoCad 2006 ADT\\Configuration\\AutoLisp\\context.lsp" '(princ))
Notice I included the entire path in this example, I do this just to eliminate the possibility of loading the wrong file.
I was taught when I started to NEVER modify the AutoCad files, add a custom menu to load your tools. I know alot of people differ on this opinion and I'm not going to tell how to do yours I was just telling you about ours.
Will