Faster Than Light Travel: Means wormholes, which you have to drag to where you want them STL first. (Or, for transmission only, tangle channels – which, for the physicists reading this, do not work by Quantum Entanglement As We Know It.) For more details of which, see Cool Gate, Casual Interstellar Travel, and Corralled Cosmos.
And yes, faster than light travel, when combined with appropriate kinds of slower than light travel, absolutely does result in causality violations in the Eldraeverse. (There are rules to govern which causality violations are possible – of which the short and mostly accurate version is “predestination paradoxes yes, grandfather paradoxes no” and various sophisticated computing techniques – “acausal logic” – make use of this fact. It’s fun!) Indeed, sometimes physics students are taken on (lengthy) field trips for the simple purpose of watching effects preceding causes. It’s a fun day out for all the family! (Even the ones who may not have been born yet.)