To address 2 posts...
Jewish community in London is centred on Hendon, but spreads from Belsize Park all the way up to Elstree - a lot Jews in their 20s and 30s have ended up moving to Borehamwood. The Jewish community in the East End of London is really quite small now, and the number of Jews in places like Ilford is shrinking - Ilford is increasingly becoming more of an Asian community.
The dominant LCC at STN is Ryanair. I believe they tried a Stansted-Brussels Charleroi route a few years ago (Eurostar at the time were running from Waterloo) but that it was dropped fairly quickly, presumably because the train was still too quick in comparison. A Stansted-Beauvais route would probably have the same problems. Easyjet have been shrinking STN as it's not a great money-maker. Which other airline would want to run a STN-Paris route ?