I did not use menues or toolbars as of yet because I am not entirely sure I like their appearance in Tk. Actially I know that I do not like their appearance.

But they look like standard menus... you're just reinventing a toolbar without images... users of your product would appreciate them.

As far as keyboard shortcuts I have created a few custom binding. Are you saying their is no place that lists thge shortcuts? Like in a help dialog?

Yes, there is no place that lists them (like a help dialog), and the critical ones are missing (Ctrl+O for open, Ctrl+S for save...)

What do you mean with regards to "working with a buffer"?

I click the New/Clear button. I type. I don't click the save or save as buttons. What do I have? That's right, an in memory buffer (probably a Tk::Text object).