For one thing, never ask questions like "How hard would it be?" and "What does it take?". After seeing those I would have stopped reading and voted to close immediately, and probably downvoted too because of the blatant disregard for the guidelines.
Think about it. What exactly would a reasonable answer be that explained how hard it is? There is no information in Oh, it's pretty hard or You'd have to know what you're doing. Questions you ask here need to be answerable quantitatively so that they can be judged right or wrong. Otherwise you end up with a lot of meaningless opinions. If a question about how long the string needs to be can only be answered that it has to be "long, but not too long", then it's a bad question and doesn't belong here. This is a engineering site, so we deal with real numbers. If you can ask about the string and a useful answer is 3.1 m ±100 mm, then it fits this site much better.
So how do you ask about designing a motherboard here? You don't. That would be too broad, even if asked in some kind of quantatative terms. Your overall question simply is not a good fit for this site. However, you could probably ask specific questions about motherboard design if asked right, although you have to be careful that the answer isn't something you look up in the appropriate datasheet.
Another more general thing to do is to avoid babble in a question, like your first paragraph. Lecturing when you come here to ask something is a bad idea. It often makes it more difficult to answer a question when the OP tries to lecture and then makes various mistakes. Answering such a question would then first require dispelling possibly religiously held beliefs. Someone that tries to tell us something instead of just asking is giving the impression he isn't ready to really listen to answers anyway, so I usually vote to close and downvote questions like that without even reading to the end.