+1 to most of wct's comments.
In particular:
1) On level 3,
https://www.warlight.net/SinglePlayer?TemplateID=760632 the challenge reads, "At first, the enemy will have more income than you", which is not true. Just dont give Switzerland to the player, and it all works
2) "The double-border scenario (
https://www.warlight.net/SinglePlayer?TemplateID=760638) is perhaps a bit hard for a beginner player to win (at least, to win it quickly), if they don't know how to use stacks, or how to beat the AI on equal income. So, maybe you could include sections about these skills earlier than this scenario."
To stress the double-border vs. equal income play, maybe give the player +2 or +3 income elsewhere (+2 is likely enough), which is not enough to win but that will boost players play once the bonuses are broken.
3) Probably more has to be said about paying attention to move order/priority and e.g. using first move to move a large stack into a territory enemy is likely to attack so that the enemy runs into it and losses a lot, etc. Will help with equal income battle, like the one in unmodified double-border scenario
4) +1 about AI not attacking until large advantage, need to lower player income/raise AI income in those scenarios
5) +1 to making examples more obvious, like the teal vs. green on the greek map. The bonuses seem non-standard, and it is not clear if green has the north or not. One can think that if not breaking the 4 bonus makes more sense etc.