I definitely recommend Java. It has the right level of difficulty and the right features that a novice have to face and learn. POO, compile, config files, libraries and many other concepts that prepare you for any other language out there. Also Java always means high performance development, which means that if you are good enough it could take you to collaborate with large and high budget projects. So Java definitely puts you in a good position in the market and of course provides you with powerful knowledge.

The comment of Ben Flowers and its responses in this article http://www.infoworld.com/article/2883328/java/java-vs-nodejs-an-epic-battle-for-developer-mindshare.html?utm_source=devmag.io (can't generate comment links in this page) make the things clear for me. I personally like Vert.x http://vertx.io/ concept, looks very powerful.

Well it really depends, do you see SAP User Interface? It's not precisely good modern design. Most ERPs out there keep their UI as simple as possible (in terms of design effort). Even requires training and certificates to use these tools in a proper way. So depends on what kind of app you gonna create and what kind of users will use the product.