Overreacting?

I have to say, I would let #1 and #2 slide, also. It's over. You had a great day. No reason to dwell on it. HOWEVER #3!!! What in the world! I never heard such a thing. You damn well should go to the wedding and make sure to take your flowers back!!! Do the same thing to her that she did to you. I don't mean from all of them, but definitely replace the two she took from you.

I think im in the minority here but i wouldn't be upset about those things.

The MIL wearing ivory/cream well she should've talked to you about it. I went shopping with FMIL and i saw this dress and told her she had to try it on, she didn't want to bc it was a champagne color but i told her to just try it on. It was stunning on her and she still felt uncomfortable about the color but i insisted if she loved it to buy it. I don't mind and its something i know from beforehand, not like a guest just showing up and not knowing their intentions of wearing a similar color as me.

The BM's thing, i dont know i assumed they are allowed and i would even tell them to go in there.

The favor thing is tacky but its just that, nothing to get mad about. Did she know it was put aside for you? maybe she thought 2 guests forgot to take favors and why let it go to waste. I dont think she did anything on purpose towards you to upset you. If it were me i would just be like 'oh wow aren't they tacky' and let it go. And definitely not something that would make me not go to her daughters wedding, especially since the person whose wedding it is, isn't the one who did this.

We all need to choose our battles and i think these are things that just need to be forgotten. You married the love of your life, had a beautiful wedding and have the rest of your life with this man. This is a blessing and small things like this shouldn't even be a concern.