April, I am so sorry to hear about your dad - and don't fret about venting this is why were are all active on the forum!
As for your FMIL - gawd... well, I do have some sound advice in relation to However, now his mom is throwing another guilt trip, becuase she wants all of her friends to attend and other people that I have never met. I am planning on having a reception back home, but she is still not happy with that.
In our case we experienced a similar situation - our solution - invite everyone - this is IMO a secret beauty of a DW - those that show, show. It's that simple! Many of my mothers friends said they were coming etc etc... I heard numerous 'I better be invited' statements.... but when push came to shove, two of the twenty of her friends are actually coming.
PS> we aren't doing an AHR....