When an attack like the necromancer staff is used, do you have to do damage to heal a heart, what about other character?

According to the rules it appears not, just confirming.

Thanks,

The only combat effects that require a wound to be dealt (unless otherwise specified) are conditions (poison, disease, stun, etc.) Anything else (knockback, wither, recovery abilities, moving the target, blast, etc) do not require damage to be dealt.

That is correct: conditions are the only surge ability that has a conditional requiring damage be dealt (hahaha, conditions, conditional). All that is required to use that surge is that a surge be rolled, and that the attack at least hits the target.

Thanks,

The attack has to be a success and have the range to hit the target otherwise you can't even spend your surges.