I'm afraid your questions may be a bit too broad for this forum.
If you want my honest advice, I would say whatever vision you have for what you are building is maybe a bit too much for you to take on right now. I would highly recommend trying to come up with a much more simple game, that maybe has one or two of the elements described above... or maybe even just parts of the elemnts.
For instance, start with just getting a text box before you worry about adding a portrait to it, or create a simple game that allows you to click and drag things around to learn about mouse manipulation. Spend some time in the tutorial forum. I know there are some very robust dialog system examples with animated portraits and typing text, etc. But until you get your hands dirty and start trying to figure stuff out for yourself (one problem at a time) most complex tutorials will probably be too hard to make fit for your game. Just my opinion.
Oh, and if you haven't yet, read the manual. Yes. The WHOLE MANUAL. Cover to Cover. You would not believ how helpful it is to have even a passing knowledge of what Gamemaker can do.
If you decide to start something smaller, and you need some more help, feel free to PM me, and I'll do my best to give you some guidence.