The only change to Ice spawns is the addition of the "groundwater" layer on planets with grass etc. The ice lakes on planets will still be present, and there are also still some solid ice asteroids.

It's certainly possible to use Hydrogen to reach space; the thrusters are just as strong as they are in vanilla, but the tank sizes are significantly smaller, and the thrusters burn fuel faster. This means a Hydrogen ship has to carry more fuel and less cargo.

Rocket Fuel is basically just a more energy-dense fuel, which means you can make ships more compact, carry more cargo, and travel further without needing to refuel. The downside is, of course, that Rocket Fuel comes from Oil, which has to come from planets.

i recommend to re-balance the thrusters in a way that you have 2 or three tiers of them: first hydrogen tier as it is now, second tier more efficient (basically you get the vanilla settings) third tier even better. The same thing could be possible with the rocket fuel.
I would like to have the same idea with the jump drives: either a low-effiecient jump drive relatively mid-game or a small grid type of low efficient jump drive.mid game and the standard one as it is now.
Another idea would be to get a method of refueling rocket Fuel in space or moons. I fear no one will use rocket fuel if there is no emergency method to refuel in space

I'm having a helluva timer finding asteroids around Pertam. Only found 1 so far, fortunately it had Uranium on it. As far as rocket fuel in space, organics are required and therefore implausible. Uranium or Solar should be good enough for space power generation, but I need to find platinum. I was going to challenge myself by not mining anything but Platinum, Gold, and Uranium on asteroids, needing haul everything else up to space...and making my first interplanetary journey require a several hour trip without a Tantulum jumpdrive. Not having platinum is ok though, more of a challenge. Rocket fuel is INCREDIBLY powerful stuff - the engines produce an INSANE amount of newtons. Just build a frame of them all, and inspect the stats and figure out how much fuel you will need. There are 25kL small grid tanks as well (I have a rocket fueled vertical mining ship that works fine in 1.2G with a 400t payload). For me, finding the end game materials on other planets only is a good challenge.