As neo said to the architect you still have't answered my question. I was asking seriously. because i edit my gameplay a lot to remove weaknesses.
chill out, he wasn't dismissing you, just trying to lighten up the mood of the forum. There is always someone who will provide a answer. It may not be what you want, but it will be a answer.
Question one, what is created for vanilla almost always goes into Random World Generated, we will find out at the release, they don't always sat while they are creating.
Question two. not sure what you mean, especially as I don't play on servers; but from what I have gathered talking to those who play on them, they are just as occupied, probably more so as there is more to do, generally more POIs, more loot and wider variety of zombies. To get a idea of what the mods are like, just do a search on youtube to see the different mods, download the modlauncher found here on this forum in the mod section and play it, if you want PVE or PVP, there are servers that can be found,, or join a discord of a youtuber you like and play on their server.
I know a lot of people who play mods and they don't visit the forum, don't have the time, don't like the atmosphere here, just aren't the type to enjoy chatting with a bunch of strangers.
What makes a playthrough hard? That depends on your experience. Do you have lots of hours in playing this game, or similar games? Do you like the challenge of living in danger 24/7? Insane, shorter days, longer nights, max number of zombies, dropping everything when you die or doing dead is dead, where when you die you have to completely restart. Nomad so wherever you go you won't have a base to protect you especially on horde night and have to rely on what you loot to stay alive. Mix and match. Go with what you find challenging.
As for mods, some are more dangerous not only by what you face but what is left out. Watching videos can give you a idea, reading remakrs on posts here in the mod section of what players and also in general of what mods are like. And mods change, War of the Walkers started out with a lot of loot, food and somewhat easy to play, geared for people who were more for exploring and not going wild over fighting zombies. Now, it is much hardier, quests are more challenging, less loot, almost as bad as vanilla, making anything is much harder, just about everything requires find a book or magazine to get the skill, have to advance to be able to even use certain things, can't use a builders workbench for example until you can build one of your own, same with one of the special forges.
Hope that answers your questions, I'm not the expert here, others are so they may give better answers.