I have some old slabs that I believe are Vermont slate… good thickness of 1/2″ to 1″+ with nice colors including, dark grey, light grey, red, purple.  I am planning to make a walkway out of them.  Two Q:
 
1- Can the slabs be cut?  If so, what is the best method?  … and can I consider rounded
cuts?
 
2- I am planing to lay them directly in the topsoil (they were sitting directly in topsoil  in my backyard for 10 years, so it seems fine to lay them this way).  Location is Long Island, NY.  Any issues doing it this way?
  
Thanks