1. Nymphs, because they heal themselves very well (although Ents are practically useless).
2. Probably Wind Spirits. Because of their agility.
3. If there are artifacts that allow the hero to shoot without penalty, I take the old ones. Otherwise, I take the new ones; they have one shot that's as good as two from the old ones, and even more powerful, in my opinion.
4. Here, I usually take the old ones. Lightning is expensive.
5. I haven't quite decided. It depends on the situation.
6. Trading defense for attack is great. I take the Altos.
7. The old, reliable Crystal Dragons are still good.