There's no point in reading the novella. There's not an ounce of fanservice or romance in the entire manga. Everything revolves around leveling up and solved by Deus ex machina. But the artist is good.
It all makes sense because we're talking about profits. Matches are the worst thing you can think of. Even rolls of cloth - as someone already wrote - would be much more profitable.
I thought this manga didn't make sense, but it turns out it has a hentai component (+NSFW pages for each chapter - which aren't here). It all makes sense now.
Clearly you can't make electric lights, but you can do things they can't. Especially since he can carry the tools he needs with him. You don't have to look far. Yeast + modern distiller = proprietary brand of alcohol (yeast was invented in 1881). Or like in Ascent of the Bookworm she did -...
Again, the simplest shampoo is made easily. No one is saying to start producing paste or any complicated medicines. But he can use what our world provides - a lot of ready-made tools.
Depends on the industry. It is enough to start with a couple of people to make profit. He has cheater options with which unrealistic schemes are available.