1) A list filled with hundreds of options before a new player ever gets to play is one of the most off-putting things you can do. I quit Dwarf Fortress first time I tried it because the LNP did exactly that.
Next time I tried vanilla. "Create New Wordl" - What could be more simple than that?
2) Please don't dumb down the game, no. It's called challenge. Consult a wiki if you don't understand or don't want to think about puzzles in a puzzle mini game.
3 and 4 sure, but basically that's how the system is supposed to actually works. Run a decent fortress and dwarves will find enough to keep them unstressed. Needs more work though, as you say, you end up checking individual dwarves, at least for the needs system (not that needs lead to tantrums so it's not really that important).
1. The current basic world gen has 6 options. Adding about 2 more to control monster/seige spawns won't break the newbie experience, especially if they have indicative names. "Werebeast spawn rate" is an easier mechanic for new players to grasp than, savagery, for example, just because it's more relevant to the newbie experience. I didn't know what savagery even was until about six months after I started playing, because to my noob eyes, it had little to no effect on my world, and I only learned about it while looking up a world generation tutorial.
2. That doesn't mean get rid of moods or change them ultra significantly. It means get rid of moods asking for stuff that can never, and will never spawn on your map, (Looking at you shells in the desert), fix the fact that certain moods are worded in a way that trips up newbies. Again, the cloth example was my first 3 experiences with moods. The moody dwarves all wanted silk, but all it said was cloth, I could never figure out why my moods wouldn't work until someone on the forums explained it to me. There might be more than one example, but the cloth issue is the only one I encountered. The whole "maybe later, you can have the option to save a moody dwarf that can't complete the artifact", is a side dream and if it happens, it shouldn't be a sure thing, it should be EXPENSIVE, and you should not be able to do it for every moody dwarf.