There are likely numerous ways to approach creating something like the timeline you pointed out. Your best bet is to study the timeline you pointed to and then create a simple version of it and see what works and what doesn't--Try to devise a modular approach, where each entry has a generic form consisting of a few inter-related objects. That way, creating each entry of the timeline will follow some general process each time. As you develop an approach, you may come to realize a dynamic presentation for the timeline information.
If you aren't very familiar with Flash, then you should use this project as a means of getting better acquainted. It's unlikely that anyone here is going to take on the role of being your personal mentor, so your best bet is to dig in and create. When you run into a problem, post again with the details of your design and the code or design element that is not working.
Despite your outlook on tutorials, they were created with the intention of trying to help people learn. There are alot of them out there, some good and some poor, the good ones were created for people who want to learn, and the worst ones were created more for the people who wrote them to show what they know. Yes, they lack the handholding that you might get from having someone watching your every move, so if you really feel you need someone to provide hands-on direction for you, then you should probably take a course in Flash design.
The only way to conserve on the size of the file is to control how much content you place in the file. If you have alot of large (MB) content, then you will probably also have to become familiar with managing content dynamically, and that is a whole other realm of design that takes time to learn.
I'll venture into the wilderness and return if I have any particular questions.