My understanding is they are only guaranteed a top 4 seed. One division could conceivably have 2 of the top 3 seeds. Is this correct?
Yep you're right. One division could even have the top two seeds if the two teams have ridiculously good records.
They only get a top-four seed but as said that doesn't guarantee home-court advantage. See recent Utah/Houston playoff matchups.
You're right. I meant to say they're guaranteed a playoff spot, but not HCA. Sorry for any confusion.