Potentially Having to take family off guest list!

So I have posted here before and I won’t get into it too much but we do not talk to my FH side of the family at all except his brother. His mother sister and his sisters kids are extremely toxic. My FH sister is a 38 year old felon living in a one bedroom at her mothers house with two kids with no job, car, drivers license and all that, she has had cps called on her numerous times and has once threatened to do it to us because she thought we called although she had no proof and we didn’t. At one point the police were called on his mothers behalf and she was even more threatening once the cops told her she absolutely had no say in the matter in which she called them on me for... once we moved out we cut them off completely. We invited his brother and his girlfriend and the their two kids to be apart of the wedding party and they didn’t wanna because it wasn’t right that his mom wasn’t gonna be there... then Sunday I told his brother that our engagement party is this October 19th and my FHs sisters daughter went and changed the day of her daughters second birthday to October 19th instead of October 26th and then had the nerve to send me a smart ass message saying it’s funny how our engagement party is on the same day as her daughters..!!! Except she doesn’t realize that she posted on her Facebook that she was having it the 26th and made the change the day after his brother was invited to our engagement party? It’s vindictive behavior, it’s in hurt that you won’t be apart of my life so let me see how bad I can hurt you and this is why we don’t have these people in our lives and they don’t see any problems with their behaviors. His brother said he’s coming but hasn’t officially responded to the invite and that’s becauae he’s not gonna pick his great niece over his brother because the mother isn’t invited and he isn’t gonna day not going or going and then look bad. He will make a excuse on why like an hour before the party starts. I’m nervous they are just saying that the 4 of them will come to the wedding and then just not end up showing up and that is almost $400 because it’s about 97$ per person after tax and everything. That’s a lot of money to just waste on somehow who will probably say they are coming and won’t show up and if I do say I don’t want them there because of this kinda drama then they will make sure to go to hell and back to make things hard for us even if that means then showing up and having to be forcibly removed from our home because if his mom and sis show up talking the big talk about how I said his brother can’t come to the wedding , she won’t leave if told to because they think the cops will take their side except it’s my property... I really don’t know what to do. Either way they are doing everything they can do throw drama around including going to my FH job and saying stuff to his CO workers about how my FH “hates” ten for no good reason