1. Without wanting to offend I think it's quite funny that you think so, because before Prenzlauer Berg became what it is today it was one of the most prominent "art districts" in Berlin, and many artists had their workshops there (https://en.wikipedia.org/wiki/Prenzlauer_Berg). Now as you say it's mostly an area where hip and affluent families live in the many luxuriously renovated old buildings (Altbau). Seems gentrification has progressed so much that people don't even remember what the neighborhood used to be before. That said, the process wasn't triggered by large tech companies setting up shop there, more by the choices of affluent people moving to Berlin from other parts of Germany. Swabians are particularly hated for allegedly moving there in order to live in a big city but then slowly turning that city into the small Swabian town they moved away from in the first place (I don't think it's a very fair judgement though).

2. That's what I said, and I think it's sad that Google won't open the campus there, as I think the area and the city could profit from it.

Also, this is a personal opinion but I think Kreuzberg is far from being a "haven for artists or counterculture". Already now the district has some of the highest rents in Berlin and many flats are being rented out as AirBnBs (often by the same people that complain about companies gentrifying the area). Also, the counterculture that you're describing can be quite snobbish and exclusive as well, at least for people that don't conform to the Berlin "hipster" ideal. I think Berlin really needs more corporations and large enterprises that set up shop there and create jobs, as the startup ecosystem has so far failed to deliver much in terms of well-paying jobs (at least if you don't want to work for Zalando). Just my 2 cents.