1 – ‘DumpACL’ or any of a dozen shareware programs. Microsoft by using a ‘metadata’ collection for AD creates a huge amount of information which requires some practice to parse into knowledge.
2 – Based on your 1st question, the answer to the 2nd is you don’t import host information. When you setup a computer, presuming Windows 2k/XP, and get to the network connection one of the advanced entries (on the DNS tab) is to ‘register this computer’. The checkmark will push an update to AD/DNS each time the computer logs in or changes IP address. No manual intervention needed.