You can check energy drain in data/json/vehicle_parts.json. The value “epower” is max energy usage/production.
There is no strict limit on weight supported. It will simply slow the vehicle down. Volume limits are now displayed in vehicle install menu.
Yes. In ASCII, they’re brown. In tilesets their tile should look different too.
You can also harvest pines for bough and cones. Cones can be used to make a snack, bough can be used to brew tea that can then be used instead of broth to make soup (pine tea doesn’t rot, so it’s a good idea to stockpile some).