Going fast needs smooth roads. But at least a couple of them are having fun.
As long as they don't follow modern conventions of naming race horses...
Naming animals after what they sound like is kind of basic.
Really likes to help out. Like a large dog.
She's half-way camouflaged on that roof. Just needs some hair dye.
Honestly, two days is reasonable for a manga like this. Usually it's like an hour or two.
I don't think that suspension is soft enough for water.
People didn't invent most things from scratch. Pretty much everything builds on something else. Most is about combining various materials, techniques, and ideas.
The hardest part about making a knife is getting the forged blade perfectly straight. Grinding the edge and sharpening it is a bit easier, and that's what makes it cut well. Or most of the time, how thin it is and the edge angle.