Myrm wrote:But what do heat sinks do? And why do you think it's better for me to lose the shield generates which will make my shields weaker? Considering I have no weapons that seems like a crazy idea to me.
Heat Sinks rapidly remove heat from your ship, you assign them to a button, when your ship reaches a damaging level of heat you fire off a heat sink and it takes the heat away. Basically you shoot off the red hot lump of metal that you ship has been channeling all it's heat into. (Note that they have ammo)
Why use them? Well out in the deep things can go wrong, a typical situation is jumping into a system and finding you are between two close binary suns (happened to me more than once), your heat starts to go up rapidly, you fire off a heat sink and your heat drops to zero and you SC away. Another thing is getting a bit too close to something like a neutron star, you get pulled out of SC, but now you are too hot to jump back to SC, again fire off a heat sink and away you go.
As for the loss of shield strength, well out in the black there is (currently) nothing we know of that will shoot you, once out of the bubble there are no hostile NPCs (that anyone has ever seen). Mike Brookes has hinted about something being out there, but he's probably playing with us, or it's something for a future patch.
People have travelled hundreds of thousands of ly out in the black and the only danger is astronomical (e.g. binary suns and shields don't help with these) or carelessness.
The only need I had for shields on my trip to Sag A* was for landing on planets.