Look, I already don't have a lot of time and I really enjoy building things but I don't enjoy recording or editing videos. So, in the time I have, I'd rather build stuff than edit videos which would only make me have even less time for building.

You can download all my builds, dismantle them, examine them and check how I built something. I trust in peoples' ability to find patterns and ideas themselves and maybe apply them to their own builds which will develop and create their own unique style. That is, if you want to, of course. You have to put some effort into it yourself, I won't present everything to you on a silver plate (the video).
I present to you the build I made in its entirety to show what is possible, but how to make it, you have to find yourself :P

It's trial and error, really. Copy what other people made (for private practice, not for publishing xD) and get a feeling for how they built something. If you like it, incorporate that way of building into your own builds and over time you build your own building style composed of the things you liked about other people's builds and of what you found yourself while building.

Just get started and try something! It will develop over time :)

Most likely not, since it would only be a box with windows xD
Why don't you try it yourself? I'm pretty sure you can do it ^^

Hm, a bus should be possible as it ranges in the same size category as a truck. Things only get really tricky when they're smaller than a truck.
After I had made these trucks, I tried to make a 1:1 pick up truck which was the size of a car (2 blocks wide, 2 blocks high and 5 blocks long) but it didn't look very marvelous xD

Thank you very much :)
It only is easier when you can replicate it, when you have to come up with the design 1:1 is more difficult than 1.5:1 because you have less space to put detail in that would be necessary to make the vehicle look cool or even just like the vehicle it's supposed to be.

I already made a submarine and a ship (and a hovercraft and a floating van). You can find them all in the My Watercraft collection.
Look, I don't build something if it's too similar to something I've already built. If I built the Plymouth Hemi 'Cuda, it would most likely be very similar to either my New York Taxi Cab, my Dodge Challenger or my Dodge Monaco Police Car.
I'd advise you to just take one of them and modify it (remove sings from roof of taxi cab or remove lights from roof of police car, change color) until you like it.