Most of my past projects are rather simple in terms of navigation. A simple dropdown menu (Superfish, for instace) works with most of them.
Now I have a project that requires content to be separated into, let's say, 7-10 immediate subpages and one subpage (or menu option) that requires 3-5 suboptions. In other words, 7-10 top level options and only one of them which will require some 2nd level nesting. It's just the way content is organized.
Because this out-of-order option has 3-5 suboptions I cannot/don't want to move them to the top level because that would increase the top level to around 15 options which I think is not a good practice.
Also I don't want to introduce a full blown dropdown menu like superfish for this site because it would look silly. Most top level options and only one option with a dropdown opening...hopefully you understand.
When looking into other options I came up with this idea that I used to implement few years back, before introducing Superfish into almost every page. It's an idea which implements two menus. One at the top level and one per subpage level.
Since most toplevel options have no suboptions, this would only show the 2nd level menu on one of the subpages. I could render this second menu as a tab strip.
Hopefully you will be able to make some sense out of this and be able to advise on what the best practice would be. Would this kind of design make people confused?
Question 2) What is your general advice on using unorthodox navigation? Something out of the box beyond the normal horizontal or vertical menu. For instance, I have this idea of using a navigation in the form of number keypad (3x3 options), since most pages will be refered to by one single word? It looks nice and it fits in the design that I've developed (1/3 of the 980px space would be occupied by this "keypad" and the other 2/3 will be occupied by the content slider/slideshow).