The Dreamhost control is different in design and function than cPanel or other commonly encountered Control Panels. You get a Control Panel for your account, from there you can assign Control Panel privileges to additional users on your account.
I’m not sure what you mean by this, but you can customize DNS records for your domains.
Yes. How “well” they run, of course, is very much dependent on how well they are coded. Certain PHP functions are disabled on shared servers for security purposes.
There is a great deal of this kind of information available on the Dreamhost Wiki