If i were to stand jupiter now with a telescope would i see life on earth 30 years ago? and if so :

 

1. if someone at that time was using a telescope and aiming at my exact position, could he see me looking at him?

 

Also, if i was travelling faster than the speed of light and i looked back could i see the past by nanoseconds (etc), could i interact with the past through this method?

Since Jupiter is much closer than 30 light-years away, no. But an observer far way could look at you and would see what was happening at a time d/c in the past.

 

Traveling faster than c would, hypothetically, allow you to interact with the past. It violates causality.

You will be interested in Roemer's work (1644 -1710). In 1676 he made the first measurements of the speed of light based on careful observations of the moons of Jupiter.