Manipulating space and time may not be as scifi as we tend to think. Your brain manipulates time. Or at least how you perceive it. Like when you're extremely bored to the point where it's agonizing to the point that it cripplesv you, and you can feel the weight of every slow tick of the clock. Contrasted when you're having the time of your life and you blink and 3 hours already went by. Time didn't necessarily change, your brain changed how you perceive it.

Maybe the weapons we have manipulate your space time, rather than thee space time.

Or maybe we do just have insane crazy weapons/ items that literally manipulate space time. Just a thought

It's impossible to return a table tennis ball if we measure the perception-reaction time by synapse electrics, they go so fast that they go past us before we can react. So how do we do this? Time crystals in our microtubules, these are structured hydrocarbons arranged in a lattice inside a hydrophobic pocket. The time crystals regulating these pockets can shuttle backwards and forwards in time to see danger coming and warn us of it before we even see it. I hope I have this right as it a v complicated subject.

There's plenty of universe out there, that aliens could reasonably avoid us

Think about it. Do you care what an anthill in china is doing right now?

I tend to believe that if a species has the ability to leave it's own solar system and go intersteller, it's evolutionarily required to be peaceful. Due to the technological advances and their power/destructive capabilities to travel such distances, malevolant species would obliterate themselves long before achieving this. Baddie, intersteller Star Trek type species don't exist.