1.There is a huge map, and you can explore every bit if you want. 2. If by levels you me areas where you do side missions, I have no idea but i do Know that there are odd jobs on billboards or something to clear out bandit hideouts. If you clear out said hideout, another bandit clan can move in or mutants so you can replay it but with slightly different gameplay because of the different fighting styles of each enemy. 3. It is what id software calls "open, but directed". This means you follow the story [levels] but you can explore as much as you want (you also can continue exploring and doing side missions after you beat the story).4. There are quite many cities or settlements for the parts of the wasteland they have revealed but there is going to be quite a few more. Out of these settlements there are big towns that are more industrial and a lot bigger than the others. Two of these big towns are wellspring and subway town however they have said there is a third one, but haven't said what it is. The wasteland is broken up into parts, kind of like countries, but you can move freely between them without loading a new section. The names of these parts are The Wasteland, The Bone Wilderness, The Eastern Territories, and The Southern Territories, however it might be different, but these are the names i've gotten from gameplay and interviews. 5. Its not released, but there is alot that they've talked about and more, there is atleast 10 to 15 or more that thaey've shown and possibly more in the final game. 6. As far as they have released, all you can do is customize armor pieces or sets, and possibly things like gloves and shoes, but not much else ( might be more in final game). Hopefully this is helpful.
1. I would hardly say the map will be huge compared to say Skyrim, it might be but I doubt it, map size isn't confirmed anyway.
2. I don't think this is confirmed, if you can post me a link I'd appreciate it.
3. I believe "open, but directed" refers to the map rather than the story (there are set pathways in some areas).
4. There seems like there will be a few, but other than those three they will not be very large, and even those three are hardly what I would call metropolises from what we've seen.
5. There is supposedly atleast four for each weapon.
6. All that has been said is that you can change your outfit/armor, and that includes all parts, unlike an Elder Scrolls game in which you pick your greaves, boots, cuirass, helmet, ect. I'd say it is more like Red Dead Redemption's outfit system, in that you can't customize individual parts, but you can pick which one you want to wear and they all come with different benefits.