Weddingbee boards

Sweet and to the point summary: my fiancé and I are getting married next year. My fiancés parents will be giving us $2000. The same amount they gave his older brother when he got married. My fiancé and I will be taking care of the rest. My mother does not have the money to help out with the wedding. Also two notes to consider: my fiancé and I live with his parents and will still be living there after we get married but only for a short while.

The issues:

My FMIL...she is incredibly sweet. However, once in a blue moon (and now every other day due to the planning of our wedding) you get to see her other side. Defensive, intrusive, opinionated. Me, being the future family member, doesnt stand up to her. I just kinda smile and nod along. She thinks she "knows" what weddings are about these days. She got married an x amount of years ago at her mother's house. Things have changed. Are wedding will be gorgeous but we've kept the cost incredibly low. She doesnt agree with us using fake flowers, doesnt like our lemon centerpiece idea, we are incredibly religious and she doesnt like that our invites say "Christ" on it, she doesnt like my fiancés white tux idea, doesnt agree with sweetheart table, wants to remove MY niece as flower girl so my fiancés youngest niece can be the flower girl (although ALL three of them, including the little one are included as Jr BMs), my fmil doesnt like our favors, she told my fiancés aunt (her sister) who we are having as our wedding singer (this fabulous Frank Sinatra sounding guy) who then told my fiancés incredibly selfish, self centered cousin...who is also getting married next year, complains about my mom not being able to give money (which is NONE of her business)...and the list goes on and on.

Help! How do I tell her to nicely stop or to tell her OUR (my fiancé and I) plans are completed? Yesterday she made a comment saying they are giving some money to the wedding so we should include HER ideas. Not true right? Thats not how it goes. I have been in tons of weddings and its NEVER been like that. Should I let my fiancé discuss this with her?

Issue #2;

As mentioned above, my fiancés cousin is getting married. Selfish would be an understatement for this one. We announced our wedding date (which was originally early spring) then they got engaged two days later. She then told me their date, which was three weeks after ours. Then said, NOT asked that we move our date. Trying to keep family peace, we decided for a summer wedding. Then their were problems with date cause she keeps moving it closer to ours. Then color issues cause I "stole" her colors - which I did not. Then flower issues, etc. I asked her (oops) to be a BM. Lol I know. Despite what my fiancé wants, I cant uninvite her. How do I deal with this one? I am the mediator now between her and my fiancé, she, "in theory" will not yell at me. And I for sure wont yell or argue. She keeps giving me ideas. I told her we are like 90% done but I wont give out details for fear of her stealing and claiming ideas. Its a mess.

Any suggestions, stories, encouragement would help! Sorry this is long. I could definitely make it longer with everything his cousin and mother have done. But despite all this, my fiancé and I are closer than ever and still having a blast planning our wedding! :o)

Thanks everyone!