I'm interested in playing a witch character in a D&D 5e game. The things I want to emphasize in playing a witch are the importance of family, in particular the bond of sisterhood, and that a witch's magic offers an alternative to both physical and political power. I see these as the sort of 'subversive' aspects of witchcraft and that's what I really want to play up. I think a case could be made for the Cleric class (follower of Hecate perhaps) or an enchanter Wizard, but the clear intent of the designers was that players would use the Warlock class in building an archetypal witch – they can access a book of shadows, 'witch' is in the name of two eldritch invocations, and of course 'warlock' often gets used colloquially to mean simply 'male witch.'
When I talked to my DM about the character, he indicated that to his mind the pact and the patron are the real core of the Warlock class. His idea seemed to be that a patron could, and most likely would, expect my character to do things that she otherwise wouldn't agree to. I was planning on going with an Archfey patron, who I hope would not command acts as despicable as would a Fiend or Great Old One. To be sure, the pact can be both a source of power and a burden, but I was left feeling like my DM was going to place the emphasis on burden. I guess I'm less interested in the pact if it's played as just another unequal power relationship (something the enchanter Wizard wouldn't have to put up with).
I take inspiration for my character from the admittedly more modern and light-hearted depictions of witches in media such as Charmed and Practical Magic, where witches don't get their power from pacts. And saying a witch got her power by making a deal with the devil sounds more like an excuse to burn her at the stake than the basis for a heroic character. But I'm worried if I try to downplay the pact concept, my DM will say that I just want the benefits of the class without the restrictions.
My question: How do I persuade my DM to play my patron (a rather significant NPC) in a way that honors my vision for my character?