Hokay, please keep in mind I know nothing about Drupal 8, so much of what I comment on here may well be problems that are already being addressed or have been solved therein. AGAIN: If I make a poopoo face at something that has been rectified in D8, please don't be terribly irritated at me!
I am a longtime D6 dev, and have been working in D7 for the past few months, as well.
Core issues as I see them in terms of the mobile Web and the pan-device Web as a whole:
- Controllers need to be separated from template/view layers in so much as is possible. There is still too much munging between page callbacks/action and the rendered response. I think this is sort of part of what
render arrays aim to ease in D7, but render arrays are complex and abysmally documented. I have asked around and no one can find true documentation on them. They're far too convoluted to figure out on one's own unless one has a lot of time, which I sadly do not.
- Let me clarify: I believe in the kind of idea that a render array repr