I do hope there is time travel.  I want some warm hand manipulating history using light touches in recorded history.  Some invisible hand saving us from greatest errors.  Future is guarding the past.  Saving the past, guiding it.  Almost like a hand of God.

If they do not interfere on the premise past happened anyway, so why bother.

I would be greatly disappointed.  Light touches are possible.

You could figure out potential capabilities but it is very hypothetical and crosses into area of science fiction.

A)    They could give us ideas and information slightly ahead of time and see what will  happens.

B)       They could take small genetic samples of us so we would not disappear into mist of time.

C)      Time jump technology might be practical way to explore and exploit universe.

Mars was wet and could become green in the past.

There are great possibilities in Earth past wet and green eras without number.

D)      I like macro interactions because they are showy and fun.

Rescue some of those nazi prisoners.

Save some art and books

Cover rear of Moses columns with time machines.

Demon, that showed Jesus Christ all kingdoms of Earth.

Some shaky proofs

A)  Last time I went crazy I was able to reach 1.5 years into the past, using video tape as a targeting system. I got a glimpse of the future too more like phone call to the wrong number.  Just a laughing boy and 3-D picture with background somewhat pixilated.  Boy was seen clearly.

B)  Tunguska meteor, which could be time travel ship in distress.
C)     Spiral of fire in the sky over Norway as seen  on TV.
D)  Guy with something like cell phone on old cut out frame of film as seen on TV.