vscode its awesome.

Chennai, India

You could use next.js which uses filesystem for universal server side rendering.

I agree with you @theonlyrealtodd. The makers golang ditched both Object Oriented Programming and Functional Programming and stayed as clean Procedural language to stay away from too much Abstractions. I m very happy to work with a "Get the Job done" language now.

You could use https://wappalyzer.com/ which predicts the tech stack of the website. I use wappalyzer chrome extension to quickly find out the tech behind a website. This tool can't predict the server stack if they remove all headers though.

Polling the server at regular intervals will be very inefficient. You could use Server Sent Events or Web Socket to achieve this efficiently. These methods sends updates only when changes happen on the server. Learn More about SSE https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events. Not all browsers supports this though. or You could try sockets https://github.com/socketio/socket.io

I would probably render the page using phantomjs with php libs like https://github.com/jonnnnyw/php-phantomjs. So that most of my styles will be rendered as in my html output

No, React Native does not compiles JS to native code instead it used native views of the underlying operating system and runs the js code in a separate thread. React Native is relatively new and it does have platform parity for IOS and android. With just the html and css and little js knowledge you could get an app running of course with degraded performance. Cordova has been around for a long time and it has decent native plugins too. As the React Native platform matures it will eventually kill those.

C JS PHP JAVA Python

React presents clear Mental Model of what we are writing without worrying about the (Evil DOM) . Unlike other monolithic frameworks like ember, angular its just a thin library for the View layer. So it gave the developers freedom to use it with their current implementation easily. React's ability to adapt with current implementation might have caused this growth.