I think its a good idea.
(ive just been watching the inauguration so prepare yourselfves)
If you feel you have something different to offer and you have the ability to get it done there shouldnt be any problems with it.
Just because there are other 3d websites dosn't mean you cant create one.
Thatd be like someone saying "im not going to create a new BLANK, there are already countless BLANKS around."
If your Blank can offer something new and interesting just go for it.
I dont see the point of joining another community and offering your services. From the sounds of it you are commisioning other people to make your tutorials, rather than making them yourself and thats something other websites could be doing already.
I would be carefull about overloading yourself though. Start smaller by only focusing on the mainstream 3d programs like 3DS, MAYA, XSI and Zbrush. Once you have a good foundation to work from then start adding in all the extras.
So to conclude! As long as you can create a professional site that people want to use, that offers something different to the community, i see no problem with just going for it.
Thanks for listning