Great theme there! I also like the name.
My thoughts:
- The main_page should have the tutorial Categories displayed with a short summary for each tutorial. That way, the main_page will get updated constantly and the search engines will reward it.
- The existing main_page can be an inside page with a prominent link on the new main_page. The existing main_page is not updating constantly, so a stagnant Search Engine Optimization factor.
- You will get quality repeat visitors if the tutorials are included with sequential images and texts... the tutorial should begin with a problem and end with the solution with the help of images and text. You can also use the comments feature for the visitors to add more to the tutorial. You never know how a simple modification / idea can help others.
- You can have the summary of the tutorials on the main_page with a small image.
- IMHO the Wiki style, though great looking, isn't helping your site much because the actual content of your site can well be found in the Wikipedia.org. People would prefer Wiki for the sort of knowledge that this site has. Sorry, just my HO though. The answer to that could well be in making the tutorial site just like any other great tutorial site, with some added features (like the Wiki style, which is an overall great style for interaction).
- The immediate answer to the above that comes to my mind is: something similar to the tutorialized.com site. There are plenty of other tutorial sites that are well-established, and most of them follow the tutorialized.com style of main page and the inside pages. Your site could be likewise and with the present Wiki style adaptation.
Rest:
Great idea. For a real success, you'll need thousands of tutorials from all sort of categories. I have helped one other tutorial site get thousands of such tutorial links before. It is much easier for others to help your site with such third-party links than write great and systematic tutorials for your site. So, a put-off there for many. For those, you can start a "link to other online tutorial" with a short description and image for each. That way, you will send some of your traffic to those tutorial sites... but, you are helping your visitors by giving them great tutorial links too. If your site has quality, then those will come back repeatedly, else there could be a long wait for building the site and the traffic.
Wishing the very best
& God Bless!