I dreaded becoming a MIL because of all the negativity I heard from work colleagues about theirs
Um, that doesn't ring true. Sorry. You are what you are.
Just because other women have MILs or DILs they don't get on with doesn't mean that is just the way it is. Surely you appreciate that?
I told my future Dils my concerns and asked them if I ever did anything they didn’t like they must tell me
Well, good for you, but ye gods! Really????
Talk about snow-flakery and the current trend with being 'offended'.
You start with the premise that because you are a MIL you are likely to offend your DIL.
Many people get on with everyone. Most people start relationships hoping to do that. Some people fall out with others. Circumstances, character, incident etc, etc, all come into play.
There isn't a rule book for the MIL/DIL relationship. You get what you're given and try your best to get on, not going out of your way to offend. Some will, some won't.
That's life, actually.