Would tithe still need to be practiced by Abrahamic followers in an anarchist society in order for the Church to redistribute wealth for charity?
If they want to give money to the church I don’t see why they shouldn’t.
In a truely free society people would decide who to give their resources to for their own reasons. As long as the organization does not use force or fraud to get the money then it is none of anybody elses business.
So, if the Welfare State was facilitated via voluntary contribution, and nothing else, is it still aggressive?
How can a person in a voluntary transaction be aggressed against. Aggression requires force or the threat of force. That person who does not want to pay the money to the Abrahamic folks might be ostracised by their own community but ostracism is not force.
Being part of a religious community in an anarchy would be similar to being part of any other club or organization. That is the folks that are incharge of that organization make the rules for membership. If paying them money is part of the rules then individuals not meeting this payment/s can not be part of the organization.
So, if the Welfare State was facilitated via voluntary contribution, and nothing else, is it still aggressive?
Of course not. There’s nothing wrong with voluntary altruism. In fact, I think group selection will prefer altruistic behavior to some extent.
Don’t confuse Objectivism with libertarianism. Objectivism is just a personal ethic, although they’ll (falsely) claim to have found an objective ethical truth.