It's a bit early for me, so hopefully I won't mess anything up too badly. =P Also I'm just going to answer the ones I can before heading out. Hopefully others can fill the gaps. =) As a start, you might also check the http://geck.gamesas.com/index.php/Main_Page and the http://cs.elderscrolls.com/constwiki/index.php/Portal:Contents (as the one for Oblivion is pretty close to the same as Fallout, with some small differences).
1. Someone else can probably give you a proper answer, as I haven't used it myself yet except in Oblivion, but it has been a while and don't recall off the top of my head. I did post a reply http://www.gamesas.com/index.php?/topic/1162727-alternate-start/ about an alternate start. I guess if you create the new worldspace you could use this info to just get your guy starting there, though there might be better ways (such as creating your own masterfile and the like).
If you haven't might take a glance at http://cs.elderscrolls.com/constwiki/index.php/Category:World_Spaces and see if it helps.
2. Again, the wiki is a good place to look. Some info about http://geck.gamesas.com/index.php/Category:NPC, http://geck.gamesas.com/index.php/Category:Creatures, http://geck.gamesas.com/index.php/Category:Actors In simple terms, right click an NPC on the left side, change what you want, change the ID, and click OK. It will let you know that it is different, and ask you if you want to create a new one. Pick that you do, and you will have a new NPC.
This really is the way it goes with any NPC, creature, item, etc. from the list. Just changing the ID to something you want and can recognize and is somewhat unique (to help reduce conflicts with other people's mods, though in the case of an entirely self-contained world like you are wanting, it won't be as big of a deal, but still good practice), then saving it as a new item.
3. Not sure if you are asking how to do dialogue in general as well as the perks, or just with perks. Anyhow, http://geck.gamesas.com/index.php/Category:Dialogue is some info on dialogues, and http://geck.gamesas.com/index.php/Quest_and_Dialogue_Tutorial is a tutorial (though I haven't read through it, so I don't know how good it is). I'll try to give a more detailed bit of info if no one else replies and you still need help - just point me in the direction of exactly what you needed (how to create dialogue completely or a specific point about it - is it only regarding perks?)
4/5/6. Absolutely no experience here. Might check http://cs.elderscrolls.com/constwiki/index.php/Resources_for_3D_Modeling#3D_Modeling. That is for Oblivion, but it might let you know how. I think I've seen people mention using NifSkope and/or NifTools for the importing/exporting.
7. Again, never imported really, so someone catch me if I'm wrong here - but I imagine you could just use the same method of creating a new NPC. Just use an existing container, then click to change the object with edit model, then save it as a new one, changing things like contents, etc. as you see fit. There might be more to it, but seems like it would work off the top of my head.
You might check the above links for info, or likely can do a simple google search for something basic and check out the forums it will no doubt return. (Search things like 'import model into fallout' or similar). I'm sure other people have asked how and you might find your answers to 4/5/6/7 if no one responds here before you start.
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Anyhow, feel free to ask more specific questions as you get them. Besides the GECK website, you can just search for tutorials in Google, use the main game as examples and see what they did, or ask if you hit a wall on something. Good luck!