What kind of magic do you like the most?

In other words, Preparation and Avenger are already in neutral magic, just like the other racial skills. Let's move on: Counterspell (Sorcery), Haste (Offense), Stone Skin (Defense), Morale (Leadership), Surprise Attack (Logistics), Earthquake (Mechanics). Now we have almost the entire skill wheel, except for Luck and Education.

Not quite. In this case, we are talking about spells, not skills. We are comparing the compositions of schools, i.e., spells. That's why there are so few of these skills.
By the way, Haste (Light), Stone Skin (Light), Surprise Attack (Light), and Earthquake (Summoning, or rather, an improved version of Earthquake) do not belong to neutral magic. Only Counterspell, Morale, and perhaps half of the racial skills belong to it, and maybe something else. But even so, all of this together is only a small part of the skill wheel.

Could you arrange it so that these neutral skills and abilities fit into one slot, similar to Light magic, for example?

No, as spells. If that doesn't work, then add them to the hero's xdb file.