Could Win2000 co-exist with Win NT 4.0

My company environment is currently on WinNT4.0

We are purchasing a new server with W2K.

Q1. Other than setting it as 2 domain server, would it be possible to set the W2k server as a member server with the WinNT4.0 as the PDC?

Q2. Could I not active the AD in W2K?

Q3. Could file sharing be possible if all users are logging into NT4.0 domain?