I second this, we use Paddle on https://gimmeproxy.com . It's really nice they handle VAT automatically on your behalf (EU VAT law for online is complicated) and setup was pretty easy.
I use Node and either puppeteer[0] or plain Curl[1]. IMO Curl is years ahead of any Node.js request lib. For proxies I use (shameless plug!) https://gimmeproxy.com .
True. Several times I have resorted to putting random console.log's into the webpack core and it's plugins as the only way to figure out why the configuration doesn't work.
The text covers a lot of ground very quickly omitting a lot of "pure math" details.