2) Sometimes, the item you pick up after collecting the flag is not visible, so you miss it and have to go back. I couldn't find an option to disable the flag, or at least have a personal one.
3) The worst thing, in my opinion, is the 3-level system; it's just absurd. To level up a hero to level 10, you need to defeat so many enemies. The first lessons are always free, but you have to pay for the second one. I think a 5-level system would be much more interesting. But the reputation and skill system is intriguing.