Hi Steve,
In regards to the StoneCold skin:
1 - It was not build to have subnavigation at all. I have added 2nd level navigation on my own. There is no 3rd level navigation handling;
2 - For you to think: Your mobile site should be MUCH simpler than your full desktop site. Can you imagine people going through 3 levels of menu navigation on a mobile device. It is not very user friendly. So you should try to simplify the mobile version;
In regards to the right approach for mobile, I hate to say that, but "it depends" of a lot of factors like :
- your budget;
- how much content the site has;
- how frequently is the site updated;
Here are my thoughts in general about this:
1 - Responsive skin is nice but it my not look that nice on older browsers - even though this will be less and less of a problem;
2 - If the site's content is quite static, I would choose a mobile skin and then have duplicated content to manage, one for mobile and one for desktop;
3 - If the site's content is too dynamic with daily updates I would try a responsive option;
Those are my thoughts. I will be interviewing a great designer/skinner this week and I will be publishing his interview next week. We will be pretty much talking just about mobile development and the choices we have. This should be interesting for you to watch once it's live.
Cheers,
Aderson