Error when working with fs.ReadStream: getting empty data on last on('readable'). Why?

Question

Node.js

Hey!
Code (training):

'use strict';

let fs = require('fs');

module.exports = (res, filePath) => {
    let stream = new fs.ReadStream(filePath);
    stream
        .on('readable', () => {
            console.log('on readable');
            let data = stream.read();
            res.write(data);        // <=== здесь ошибка
        })
        .on('end', () => {          // <-- сюда не заходит
            console.log('on end');
            res.end('');
        })
        .on('close', () => {        // <-- сюда не заходит
            console.log('on close');
        })
        .on('error', (err) => {     // <-- сюда не заходит
            console.log('on error :: ' + err.code + '; ' + err.message);
            res.statusCode = 400;
            res.end('Bad request');
        })
    ;
};

CASE 1:
I pass the name of a file with a picture to the input, the picture is rendered on the client, and the server crashes with the text "First argument must be a string or Buffer" and points to the string res.write(data); - there indeed, in the last readable event, the stream.read() function ; returns null
My questions are:
1.1 - why did readable work if there is no data? (it is clear that you can write if (data) res.write(data); but this is a crutch, it seems to me)
1.2 - why on('error') did not catch the error?
1.3 - why didn't on('close') work?
1.4 - how to properly protect yourself from such errors, where to intercept them so that the server does not crash?
CASE 2:
I pass to it a text file encoded windows-1251 on the screen - squiggles. When opening the stream, I tried to specify {encoding: 'windows-1251'} as the second parameter Result: Unknown encoding: windows-1251
2.1 - where can I find a list of values ​​for encoding for different encodings?
2.2 - is it possible to somehow find out the encoding of a text file while the script is running?