Hi,
Let me try to answer your questions.
#1 What is the command to copy files from 1 Unix machine to another Unix machine, providing that the 2 machines are in the same network.
Ans: SCP should be the way to do it.
#2 How to list dynamic dependencies of executable files or shared objects?
Ans: ldd --> list dynamic dependencies of executable files or shared objects. Check out man page of ldd for more info.
#3 What is one of the disadvantages of using symbolic link?
Ans: I guess it is about softlink , then one disadvantage can be "it can be linked with the file which is not existing actually".
If it is for Hardlink then one disadvantage would be "It can not cross file system".
PS: Plz correct me if am wrong.