i agree with silverLeaf167 in that if the players don't want to roleplay, then there is no need to push them that way. that said, you're allowed to experiment- maybe they'll like it?

on the subject:
- Whispers of the vampire's blade is a Horrible adventure in my experience. there are way too many things that aren't addressed which moderately intelligent players might do. such as:
when they board the air ship the players might decide to intimidate/ persuade/ charm/ sneak past (you wanted roleplay, right?) the captain back to the dimensional closet, or whatever it was (i forgot). the same goes for the train ride, where they want to get to the more private booths where the vampire resides.

i wish i could suggest you an adventure, but i find most lacking. i like to take elements from them and incorporate them into my adventure. the persuasion of the pirate king in "eyes of the lich queen" might be a nice example you can use.

i wish you luck with your endeavor.
Kol.