You can mod two of those things very easily, maybe two or three minutes. You can set your death penalty to whatever percentage and hard cap you want in the player.config file and change the fuel gained from the various fuel sources in the file for those materials.
Just follow
this guide to unpack your assets folder, then open player.config, search "absolute". The absolute value is the minimum flat number of pixels you lose on death, the percentage value is the % of your pixels you lose on death. You can change these to whatever you want. IIRC the various fuel ores are in assets->terrain->[the first underground file]. Just Ctrl-F the various fuel ores (Coal, Uranium, Plutonium, and Sorium) and you can change the amount of fuel you get when you use them to fuel your ship. You can also change the fuel values for the rods for the last three so that smelting fuel ores is actually productive. You can also, if you really want to, edit the refining process for wood to give you more coal. You could actually do something like 1 wood -> 100 coal or something if you wanted to be super-cheaty.
As far as staying warm goes, unless you started on an arctic planet or something, you shouldn't have any problems with it. Same deal with food: just set up a farm on your ship; normally plants only grow when you're nearby, but they auto-grow on your ship. All you need is a cooking worktable and a wheat farm, and you've got an infinite supply of bread.
Also, if you dig far enough down, you stop being affected by temperature. Which, I suppose, is sort of accurate. Aside from that, just make a campfire. Unless you're wearing no armor on a snow planet, it takes absolute ages to freeze to death, and a fire gets you up to full in a few seconds. Also, if you really don't like dealing with the difficulty, carry a bed around with you. When you're hurt, just wall yourself in with dirt, place the bed, and sleep to heal. This is a pretty good way to use the nights when you're just starting out. Or you could just dig down. If you
did start on a snow/arctic planet, get out of there.
Yeah... it should be freezing underground ALL THE TIME, not just at night.
Well.. down to a certain depth anyway. Then it would get warm again. But the upper layers of the underground should be cold cold cold.
Not super cold, cool-to-cold. Underground near the surface is actually a fairly stable temperature zone; it's why digging underground in real life is a solution to both extremes of heat and of cold. It's a bit chilly, but not freeze-to-death cold, and the earth above is excellent insulation from both sun and weather. Uncomfortable, but better than being in a snowstorm or a desert day.