A. No, you can’t import into Zwift.
(Well, its technically possible, but it’s a violation of the Terms and Conditions for TR to do so.)
What you can do is use Zwift and TrainerRoad in tandem. I and many others did this last year. This guide covers the several ways you can do it.
B. That might be possible, but it’s not a direct plug and play. If you follow the steps above, this is not likely needed.