1. Energy - part of this is already there. You can click any power generating building to see the details. The biofuel generator is "special" because it needs to be full and clicked with a fuel item.
You can't easily see how much any single building uses though, only by isolating it with a dedicated power source.
For the total generation/usage stats just add a battery to your base. If it doesn't run out, you're doing well.
2. Garden patches have to be manually watered, and will dry up when you're away. They can be watered by the rain directly, so you can absolutely play this way. Upgrading them to a greenhouse simply removes this issue.
Greenhouses are also base modules providing oxygen and shelter, are automatically watered if you have a water tank. One of the tech upgrades also makes them use 25% less water.
Both can be automatically replanted by the auto-crafter, making the greenhouse a fully automatic farm.
3. Unfortunately, the auto-crafter needs a bit of fixing before any new features are added.. Not sure what is the state on that atm.
4. You can actually use the dozer to gather purple rocks. Other than that, just explore the map. The buggy makes it really easy to find multiple volcano biomes. Just remember to pack a meal and a garage setup for air.
5. There already is an endless mode - nothing stops you from loading the save after launching the rocket and completing the mission. You can play on a single save for as long as you want.