"The fact that a group of hacker kidz, likely hacking Playstation and Xbox for the lulz, can pose a serious threat to the anonymity of Tor is very not good."

This statement is in error. It has been pointed out that new relays added to the Tor
network are not passed traffic immediately.
https://blog.torproject.org/blog/lifecycle-of-a-new-relay

"Likewise last week, when Tor’s founder admitted that government agents would only need to seize five Tor directory authority servers to completely hickack[sic] the network"

Misleading. Carr says "government agents", to imply that one government can seize the
five Tor dirauths. Carr's article lists the dirauth IP addresses in his own
publication (https://archive.today/9gqLp):
128.31.0.39 Cambridge, MA, US
208.83.223.34 San Francisco, CA, US
154.35.32.5 Washington, DC, US
199.254.238.52 Seattle, WA, US
86.59.21.38 Vienna, AT
194.109.205.212 The Hague, NL
82.94.251.203 Amsterdam, NL
131.188.40.189 Erlangen, GB
193.23.244.244 Hamburg, GB
171.25.193.9 Stockholm, SE

No one government can seize five dirauths, and so no one government can completely
hijack the network.

"the growing paranoia of Tor exit node hosts that at any moment the cops are going to come crashing through the door and shut them down."

This has nothing to do with Tor's security. While some exit operators may be
paranoid, this doesn't mean Tor is insecure.

"seizing the servers would potentially expose every single user of the network until they download an updated version of the Tor software."

False. We've already established the fact that five dirauths would need to be seized
for this to happen. Suppose one or two dirauths were seized? The dirauths participate
in a voting mechanism. To skew the election, you'd need to seize a majority of them.
Five out of the nine.

"the maths required to destroy Tor’s ability to keep information secret is far
simpler. There are nine directory authorities which direct all of Tor’s traffic.
Hijacking more than half of those would allow a government agency to redirect all of
Tor’s traffic anywhere it likes."

A government agency, on its own, cannot hijack more than half of these.

"Nine plus one, divided by two equals Tor is completely screwed."

No, the integer part of nine (directory authorities) divided by two, plus one (to force a majority), equals Tor is screwed.

"Did the leaked NSA documents lull them into a false sense of security that no one
could take over enough exit nodes to undermine the network, leaving the way clear for
today’s hackers?"

I'm pretty sure that that the directory authority system was designed before Snowden did his thing.

"a network that we now understand can easily be compromised by a small group of hackers or a handful of G-men with a warrant."

Wrong, as claimed above.

"Moreover, no one in the Tor community seems to fully understand where the network’s vulnerabilities lay, nor do they have any concrete plan for fixing them."

The fact that the consensus list is not as geographically diverse as it ought to be is not something that the Tor community is exactly ignorant of.

"even tried to smear other Pando writers as child rapists"

"Russian women, especially on the first date, expect you to rape them," said Mr. Ames. http://observer.com/2000/06/from-russia-with-lust/ '"Dude do you realize…do you know how old that Natasha is?" he said. [...] "No! No, she’s fif-teen. Fif-teen." Right then my pervometer needle hit the red. I had to have her, even if she was homely' http://baruffio.com/docs/ames.html 'I took Natasha back home with me... After sex, she confessed to me that she had a three-month-old baby, and the father had abandoned her. In the "work of non-fiction" _Sex, Drugs, and Libel in the New Russia_, by Mark Ames (writer for Pando Daily) and Matt Taibbi.