Cleoraptor - your dad sounds exactly like mine. Sadly, i have lost all respect for him the last couple of years. He has put his spiteful wife above the children who truly loved him and had his best wishes at heart. He has built his own prison walls - sad, but he is the only one that can change that, and i doubt he ever will.
Re your wedding, i think Meerka is right about deciding what you would regret the most in years to come. I have been Nc with mum for a year now and married for 5 years. My beloved uncle died a year before from cancer, horrid and he suffered a lot. My uncle was a kind man who had done so much for us and mum, yet she treated him disgustingly during his illness, including screaming abuse at his hospital bed, as he was dying, because he wasn't interesting company and ungrateful cos he wasn't making enough effort to entertain her when she visited. He was in agony!!
Anyway, with one thing and another, i didn't want her at my wedding after that - i saw her for the truly poisonous woman she is. But i wanted my dad and younger siblings there and knew they wouldn't be 'allowed' to go without her. So i invited mum as well, but spent most of the day trying to avoid her. I felt physically sick as we had photos of her with her arm round me and playing happy families. Half the photos from that day are a pack of lies and i felt a fraud. I don't have many regrets in life, but one of my biggest ones has been that i allowed that woman to share my special day. At the time i did what was best cos i wasn't ready for nc, but i feel like her presence spoilt my wedding day. Five years on, i really wish i had not invited her - and i don't think that feeling will ever fully go away. I wish i could have that one day back, to do differently. Everyone is different, and i'm not saying you will feel the same, but think carefully about what is most important to you. It is so sad to be married to a wonderful man you love, but to regret how you spent your wedding day.