Salam, never feel as though you’re bothering me, i’m sorry it took me so long to reply. I’ve been busy with uni and exams. All i can give you is my opinion and advice i’m in no way an authority. I agree with your dad that discovering yourself is discovering Allah. The way i see it is, that my relationship with Allah is linear and no one can interfere or intersect. My relationship with Allah is personal and there is only one that knows me better than myself and that is Allah. Community can be important but they should never break that linear relationship i have because no one knows whats in my heart more than Allah. Allah knows me better than i do. The one thing i love about Islam is that a lot of it is practical and about intention. In my personal opinion i don’t think there is anything wrong with drawing characters. It’s the intention behind it, you know that they’re purely just characters. You might want to consider the actions and things you create and if they promote good things. i think message is quite important, you can teach people through your art, you can send good messages rather than promoting things you personally deem haram. No ones relationship with Allah is the same and there are always going to be people that tell you things are wrong but it’s in yourself that you have to look, it’s in Allah you have to trust. It’s always good to listen to people’s advice because as a whole people mean well but that doesn’t mean you have to follow their advice if it’s not right for you. I hope i’m making sense and not rambling :)

Everyone has there own opinions and that's okay, as long as they don't try to push their views onto others. I agree with you, i don't think dogs are haram. These days in most cases we are able to keep them clean and look after them. they're compassionate and loving animals. I think this idea of dogs being haram stems from a history where there were a lot of stray dogs and little modern medicine or knowledge in treating diseases they may have carried.

A couple good articles i've found below if anyone's interested. 

http://egyptianstreets.com/2014/05/14/dogs-are-not-impure-says-prominent-islamic-scholar/ 

http://www.malaysiandigest.com/news/523961-only-shallow-minds-claim-touching-dogs-are-haram-dr-asri.html

I can't tell you want to do but i can give you some advice based on my personal beliefs. I see nothing wrong with what you're doing and feel. In terms of her being a non muslim, if this isn't a problem for you then go for it. As long as she loves and respects you and accepts all that you are and believe in, including your faith and doesn't try to change you then i don't see what should stop you. If you truly love and respect each other then that includes embracing your differences and supporting each other even if you don't share the same faith. This goes both ways of course. Love is a beautiful thing and too often we limited it to these boxes and constructs we've socially created.