Okay, even so many failures, I think I am ready to share with you guys some of my experiences.
1 - Never embark on a tranquil area. In my experience, only small animals inhabit those areas, and you might not be able to slaughter their corpses for meat and bones, which is the center of your early economy. Seek for wilderness if possible. Only go to Untamed Wilderness if you're ready for some pain. Edit: Those will generally have predators, but as long you keep your necros and bones safe somewhere, your ghouls have little to fear. Also, never saw a predator that couldn't be butchered, so, yeah, more reliable than tranquil habitats.
2 - Since hunting is unreliable at best, try to build the graveyard as soon as possible and make a necromancer farm corpses there. Corpses are more important early on (because they bear meat, if I am correct) than souls, even though those are necessary for you to reach higher tiers in your game.
3 - Try to begin the game with at least two warlocks. Besides the fact that if you lose all your warlocks you're good as dead, two will allow you to search corpses and produce ether stuff at the same time. Edit: Also, two warlocks means they will bring with them 4 pets which, if butchered, will give you more than enough souls to build the Ether Gate and start your tower.
4 - Warlocks are extremely frail early on. Resist the urge to put them to fight alongside your ghouls as spellcasters. I don't even bother to bring staves anymore...
Now, three questions: ghouls only eat raw meat, or they can eat cooked meat? Do they eat rotten meat? And fish counts as meat?