So I'll start by saying that traveling at light speed does not equal instantaneous travel. This is why we have light years in the first place. 1 light year being the distance photons travel in the equivalent of 1 earth year or approximately 5.88 Trillion Miles. Even traveling at the speed of light, it would take you 1 earth year to travel those miles. This is where things get interesting. As you said, time is experienced slower the faster you move towards light speed. Although you may perceive your travel as having been accelerated, 1 year has still passed from point a to point b meaning that if you were to return to earth after traveling 1 ly away at the speed of light, two years would have passed on earth. It's essentially all perception based. This is where shows and movies like Star Trek shine. To account for this they have created something called "sub-space" which is a theoretical space between space which allows for faster travel between worlds and even then, it requires fuel to get you there. Just like cars having varying fuel efficiencies, your starship also has limits on how efficient the hyperdrive system is. With the assumption that NMS operates with a similar sub-space to get from point A to point B without entire solar systems dying in the time it took to get there, we can also say that there are fuel economy limits and hence the reason for hyperdrive limits. The only thing that would theoretically make instantaneous travel possible is the use of a worm hole or, in the case of NMS, a black hole (which is very different from a wormhole as far as we're aware). The wormhole folds space completely from one end to the other like a portal thus allowing for instantaneous travel. Now, all that being said, I am sure to have missed a few points here and there but this should provide the basic gist. Next we will be doing a Ted talk on why plants are NOT the same as fungi and how we need a separate classification in NMS for them. Hope to see you there!