I'll try to link to the particular kuntreisim in a bit but as follows:
Other than the city eruv, the central area to Har nof is a problem... (most people are noheig lehatir, but still a shayla) - Theres a large stretch of buildings along kanfie nesharim that are debatable if they count for extending the tchum.
Neve Ya'akov to the rest of the city... really doesn't connect at all. There is NO continuous chain of houses within 70/140 amos that connects to the central city... (the highways are too wide)
(Though I have heard of people asking shaylos on shabbos in quasi-pikuach nefesh situations and being told that they could walk from NY)