Not read everything, far too long.
I haven't been to an awful lot of weddings, but never have I been to one with a free bar. You get two glasses of champagne, and 2 glasses of wine at all I have been to and I think that is more than enough. If you as the guest want to get pissed, then you should fund it. The B and G have already paid out for food, disco, venue and a few drinks. And to say she shouldn't have the day she wants so that she can afford to pay for all her guests to get hammered is really unbelievable. It is the B and G day, not the guests.
I am getting married next year. I have no father to pick up the tab. My biological one is somewhere unbeknown to me and my step dad is no longer with us. My mother is a single mother to a teenager on minimum wage and is already adamant on paying for my dress as my father should be in her eyes had he been a decent father and have a role in my life, there is no way I would allow her to pick up the tab for a free bar also.
The guests will get a few free drinks, but after that, if they want to get drunk out of their skull, they can pay for their own. But I also do not expect gifts, we don't need them to which the guests have been told. I just simply want them to come and share my day with me. I also don't expect the best man, ushers, and bridesmaids to pay for their outfits or shoes. I am even paying for their hair/makeup to be done. I don't think it is right to ask someone to play an important role and expect them to pay out for the costs. For that, YANBU.
YANBU either over the invite. Everyone, even those who are single, have been told to bring their partners (even ones we don't really know) or a friend. I want them to feel comfortable, and not be on their own not knowing or being that close to the other guests. But the fact you are the best mans partner, I am very very surprised that they have found it ok to initially not invite you.
But this whole thing about having a wedding you can't afford because they can't stretch to pay for all the guests to drink themselves stupid I think is ridiculous. Why should they not get married until they can do so? It is their day, not the guests. Not everyone has a father, or another relative with the cash to pay for it.