It's the same dude doing the voice for old/new Broly . But yea, you are right about Bulma's VA. Latest news is that he lawyered up and suing them. Good on him for not backing down. I would've assumend he was guilty if he didnt.
Not always. I still prefer to watch anime in subs but the dubbing has gotten better than what it was 15 years ago. It doesnt sound like the VAs are just reading the script with no emotions anymore. I thought Broly did a good job in the movie. So ymmv, i guess.
Also, it's because of the shitty dub the 'over 9000' term is iconic now. So there is that.