Check out http://cython.org/. This project will enable you to write high level logic in python and drop to C in the performance critical sections of your code.

First of all nobody prohibits you from learning their language - on the contrary having access to lots of native speakers enables you to catch up with the language pretty quickly. "Survival German" takes at most 2 weeks to master. If you are not living on the outskirts of Berlin like I do the population is quite mixed ( ratio of natives/population: Berlin - 72%, London - 60% ).

I do agree that the trams service is average, but you have U-Bahn(metro) and S-Bahn(train) with S-Bahn ring around citi center and with this mix you can move around the city very very quickly. On top of that you have a lot of car sharing options and Berlin and unlike London, Berlin is very friendly for cyclists. My experience from cycling in London is that it's an extreme sport there.

In IT you don't need German. English is more then enough. Even though the average salaries are a bit lower then in London you still get much better overall life quality. A pizza during lunch break costs 4 EUR here, a monthly public transport ticket around 80EUR, a decent flat outside of mitte (60m2) goes for 600-700 EUR.