Secondary skills in Heroes 3.

What artifact? :confused:
The best artifact for the neck: Amulet of Divine Grace: +3 to all primary skills.
It's easier to take Leadership, and there are better artifacts.

Sometimes, instead of the amulet +3 to all, it's more useful to wear +3 Morale/+3 Luck. In battle, it helps a lot, and you can remove a bunch of small, single-use artifacts (like medals and horseshoes) and replace them with, for example, a bow set ;)
Yes, and it saves two secondary skills.