Play as Inferno.

1. Regarding the end of week 1 – I’ll take a look. It seems to be because I’m not building magic on level 1, and therefore there’s no path to Succubi.
5. Besides Grok, who else can effectively clear the territory and not waste slots on unnecessary things that aren’t needed in the endgame? I don’t know anyone. Plus, they have Logistics from turn 1.

Inferno is generally the worst opponent for the Elves, because without mana, the Elves usually don’t amount to much. Don’t lose any Imps before the final battle, and the Elves will be defeated.

I wouldn’t be so optimistic. Imps are certainly a big advantage against the Elves, but in practice, things aren’t always so rosy. First, it’s not easy to accumulate Imps, and on level 15, with proper development, the Elf has a minimum of 7 Knowledge (without artifacts), which is 105 mana, and where do you get 400 Imps? Second, it’s even simpler: against the Demon, take Sharp Mind, and the Imps will be defeated with the first spell. But sometimes the Imps still go first, 50/50, you need to be ready for this, rush to the Inferno with a group of hunters, and defeat the horned ones. If it fails, retreat and return again as soon as the Imps are defeated, and the Demons will have a hard time. But here, skill is what matters, not the race. And who is really the worst for the Dark is the Orc with the Chaos Silencer.