I've only ever made a few trips on c2c and the stuff I saw was alarming, to say the least.
The arguments and aggression from passengers (well, chavs), the need for staff to wear head mounted cameras (I'd never seen that before, even with the police) and people jumping over the gates.
What also got me was that I guess the TOC knows who most of the offenders are and it's a game of cat and mouse, and in many cases it becomes personal.
Do they keep the gates operational later than other TOCs?
Funny, OK I should say I am local to a fairly rough place on the line (and returned to a rather nicer place in what is now c2cland a few years ago after a good 15 years away), but in general I find *on the main line* (the two lines that run via Grays and Tilbury are perhaps a different matter) that it's generally a trouble-free environment - although some late-night trains can be horrendously overcrowded (and consequently mildly rowdy) if they are run, as they usually are, as 4-car sets. In no way would I describe any of Laindon. Basildon or Pitsea as agreeable places, but in general trouble doesn't spill onto the trains at those places, despite the Basildon fare-dodgers.
But repeated experiences have led me to conclude that in general late night passengers on even crowded c2c trains (again, I add, on the main line, anyway) are far more civilised than those who one may run into on late night trains on even tube lines, like the Jubilee or Met, that run through nice areas of North-West London! The other thing I've noticed on c2c trains (which I think is relatively unusual) is that, if someone is mucking about, there's quite a good chance that someone (a passenger) will intervene and tell the miscreant to stop it.
I've never seen head-mounted cameras in c2c, but I do remember travelling on one train between Barking and Grays (via Rainham) one Sunday morning that was gripped, when I was the only passenger on the carriage I was in (out of about 10 people) to have a valid ticket. A slightly surreal experience....one of them spent 10 minutes arguing with a woman who claimed to be going from Barking to a church in Upminster and who thought that it would be OK to do so travelling via Grays. The grippers basically gave up after a while, and didn't even try to tackle some blatant fare-dodging at Grays either.
And I don't know about Southend Central or Barking - probably the two busiest stations, but in general the gates are left open and unmanned after about 9/10pm at most stations (later still at Fenchurch Street), and much earlier on Sundays. They do have staff in fluorescent "customer service" bibs (replacing the far less friendly security staff they used to subcontract a similar role to) on selected late night trains.
EDIT: Now I think about it Grays and Tilbury Town (which one might reasonably expect to be the most trouble-inducing stations on the network) sometimes have security staff by the gates later in the evening. It's easy to tell when Tilbury Town is unstaffed as every single window suddenly becomes shuttered!
I'd say the overwhelming majority of problems on c2c are essentially in the category of "anti-social behaviour" rather than crime, as such (faredodging excluded - but it is not generally a "free for all", like the North London Line was in Silverlink days...) : I've certainly never felt unsafe on their trains. Both the District and NXEA lines in East London strike me as being far dodgier!