Yes you are right. Using machine language we can run program
without OS.

yes, we can

yes, if we provide memory management,cpu management and i/o
management in machine language(or implemented @ hardware
level), we can execute any program without os

no, we can't exucute any program w/o os.bcoz it controls 
all the operations of the computer

yes we can, bcz in the early systems that were without 
operating systems, we were in a position to execute the 
user porgrams (before 1956 when first os was developed)

ya,through processor only we can. 
If we know the clear definition of the Os then its become
simple.