Before you get the option for a better ship (maybe about t1 to t3), you should be able to only jump to adjacent solar systems, and always have the option to travel without fuel which would take about 2.5 minutes.
It's quite a useful idea, if I get stuck on a planet without any fuel I wouldn't want to have to go mining for ages.. And having some time to wait could be useful to do other things, considering there's no proper pause feature yet.
Yeah, besides I love traveling through dark locations for a long amount of time. Flying around space is Starbound kinda has the same effect on me >w<
Cool idea - I definitely agree there should be a second travel mode. I would think that it should be a low fuel cost instead of free (unless our ships have magical solar powered rockets), and you can select which travel speed you prefer at the computer: Fast and fuel intensive or slow and economical.
Realistically though any non-FTL travel speed would likely be used inside of solar systems from planet to planet as otherwise it'd take days to get to other solar systems in theory. Could have other race ships have different effects while using FTL, like maybe a human ship would have more of a jump drive than an FTL/hyperdrive which would basically make it reminiscent of Battlestar The actual different being though, is that Jump drives require a sort of charge time, but are faster than FTL/Hyperdrives since they're actually instant (I think). That or "Jumping" would be the ship's available method of movement before the FTL drive is repaired Or something. Though planet to planet travel across any distance is pretty much the loading screen for the planet we're going to, so instant travel wouldn't be actually possible most likely without alot of tweaking in how worlds load or generate.