Clone or duplicate the master website can be done with a rule like "replicMaster" that is described several times in the forum and also described in the tutorial video 0.d (moreless at the middle of the video).
See
www.jms2win.com/en/forum/24-joomla-multi...but-not-content#9946
You can NOT yet have 2 identical URL (domain) that make reference to different website.
In JMS 1.2.x, you need to have a unique domain URL that make reference to a unique slave site. So if you want to have slave1 as a copy of the master, you can for example create
www.mysite.com/slave1 that correspond to the slave site.
In JMS 1.3.x that will coming soon, it is possible to have several website with exactly the same domain URL that will use additional information to create variant of a same website. The variant are geo-localisation, browser features such as mobile device and browser accepted language.