It's using some of the exact same technology via python3 and oniguruma. I avoid C++ like the plague nowadays for my own sparetime coding.
Not really, but much of the extensibility that users are exposed to is documented (much of it by third parties!). Oniguruma was mentioned for textmate compatibility somewhere in the forums, so that's what I'm using too. I believe pango and cairo have been mentioned for font rendering. I'm sure you can figure out lots more via "strings sublime_text" if you really care.
Actually JITed code has potential for some complex runtime analysis which can make code faster than compiled C/C++.
I find this quote silly. ST isn't faster than other editors, in fact it's very much possible to do operations much slower in ST (a somewhat recent thread about loading huge log files spring to mind). ST's edge performance wise is in its rendering performance compared to other editors and that needs no reverse-engineering.