I had an interfering MIL too. It drove me mad at times. But I have to say that quite a lot of the incidents you mention, and which you have obviously been brooding about for years, seem very petty to me and not at all worth getting worked up about.
If she is still texting your DH several times a day that is completely unreasonable - but it is his problem. He needs to ask her to stop (or just ignore the texts and just respond once, at the end of the day.) He needs to back you up - "Thanks for the thought, Mum, but please take these toys back and don’t bring any more. We know you mean well, but as DanceHead told you we don’t have space to store this type of thing for years. Why don’t you keep them at your house." And he needs to keep it up - if he says no once but gives in if she nags enough, it’s like teaching a child that you will buy them sweets if they make enough fuss.
But you also need to speak up, politely, if she does things you don’t like, IF you think they are important enough to make a fuss about. For instance, you say that when you told her about your pregnancy she 'ruined our happy occasion once again by saying, “Oh, well, if you had bought a house near my house, I would have helped you raise this kid." ' Yet I really don’t see how that innocuous remark could possibly have "ruined your happy occasion". You were being over-sensitive and seeing insults when there were none. But regarding the name for your FIL, it’s up to you, your DH and your FIL so why don’t you just teach your DC the name FIL wants and refer to him as that? If she says anything different, I would just say "This is what FIL said he wanted to be called, and it’s up to him, isn’t it, so we'll use that."
I would also not hold back from repeatedly saying to her something like "Did your MIL use to tell you how to xxxx?" or "Would you have liked it if your MIL had ignored what you asked her to do with your baby?" (or whatever it is she's done).
Keep LC if that’s what you want and it’s not causing problems with your DH. But I disagree with the MN trend for going NC with difficult people (and the current trend for labelling people as "narcissists" at the drop of a hat.) Coping with others is part of life. You are giving her too much headspace.