jQuery lasting for another years: absolutely.
Why? Because it's got such a low barrier to entry for developers to start doing any DOM stuff, and the documentation and community around is ahead of anything out there. It may not be as advanced as the fancy frameworks, but it's extremely accessible to new people coming to the industry.
Favourite HTML5 API... hmm. HTML5 specifically, or in the "umbrella HTML5". So, assuming strictly HTML5, I guess...the History API - it fixed a lot of interactions that ajax broke.
If you mean more the umbrella term of "new Browser APIs" - I think the media APIs are pretty neat (of course there's all the APIs that go under PWA...but this is like a toy box that I can't chose the coolest thing!).
Tech: my client work focuses exclusively on node at the moment, partly around CLI but I tend to also break my work out into standalone modules (which means CLI has to support 0.10 and upwards, but the standalone stuff can be node 6).
I've just recently also started using Babel and ES6 (I know right, who knew?), but I'm not using Babel during the development, so there's no watch+build step.
Otherwise, it's node, tap for tests, travis and that's about it. I tend to work quite close to the metal.