DO they still? Last I heard Amtrak was no longer taking private train cars as too many were not in good mechanical shape and thus a large cause of their delayed trains.
Plane pollution is not that much worse than a car. Depending on what metric you measure it can be better (planes are more fuel efficient and thus less CO2. Small planes like the picture generally use lead fuel and old engine designs that pollute more) on long trips.
If you have geothermo sized right for your house and climate you don't need a backup at all. However at the expensive of installing it you can get a modern air source heat pump for a lot less $$$, and so overall that is the better plan for most people even though in many climates you will need some other backup heat source for the days that it gets too cold for the air source heat pump.
Geothermo is great if you have it, but it takes a lot of money to install for the few days you need backup heat. A regular gas furnace is a better backup.
This is not a valid question. You should be looking for a direction, not specifcs. Career is a combination if what you want to do, what you are willing to do, and what the job market needs right now. If you focus on a dream job you can get stuck with no job as the market doesn't need that.
What if I offered you a job but you had to move go the most remote Africa? Some would jump at it, others would hate it. Would you work a job where you are on the phone all day? Would you work a job in software testing? Would you be happy as a tour guide? Different people have different answers. You are allowed to change your mind later.
There is also what you are willing to go through for money. Doctors make a lot of money, but often have to work long hours and can be on call in the middle of the night, not to mention med school is hard. The world needs more engineers, but again it needs a lot of school .
So pick a direction that sounds good. Then refine it based on both what you like and what opportunities open up.