Skills for an Inferno hero.

Messengers, dispel magic, and similar abilities remove light magic spells, but this is a summoning spell.

They remove all positive effects, and Heavenly Shield falls under that category.

Speed is important, I agree. But if there was a choice between logistics and, say, attack, then attack would still be the priority. Although, of course, this is a very hypothetical situation.
For me, logistics is among the three most useful skills for a demon, along with attack and defense.

I don't think it's worth neglecting logistics in favor of attack. The hero's movement range is still more important (for any race). The attack parameter and the damage dealt by demons are already high, but for low-level creatures, a 5% damage bonus won't make much of a difference. It's better to take attack in the middle of the game when you have mid-level troops, and logistics at the beginning. In any case, these skills will come up more than once.