Well, maybe I'm imagining things, but the way he said that in his internal thoughts... dunno, it seems he get there, and not just to be sure google maps was accurate.
Howerver the fapping guy is Johno. He's the one taking pics for Zak. He said he has nasty pics of Emma.
Zak tries to ruin Emma's self esteem for month by giver her anonymous shit. By text, sure, but probably by mail to. He doesn't know that Charlie has intercepted all the mails before Emma could read them.
About Carter... yeah, he's fishy as fuck. Always had a bad vibe. At first I thought he as something against MC and was trying to torture him by leading him on a case that would trigger traumatic memories. But now, it's certain he's corrupted and works for the Hillside's powerfuls. Zak's one of them. That's why it seems David is in deepshit
I doubt some of that. MC has a little chat with Johno. Just the two of them ... and a gun.
Surely Johno can't be so afraid of Zak that he fears for his life.
From ep10.rpy
pl=MC, Joh=Johno
pl "What do you mean someone paid you? Who paid you?"
pl "TELL ME!"
joh "I can't. I'm more scared of him than I am of you!"
joh "He really would kill me!"
For that specific quote... Zak looks pretty confident in the fact he's untouchable. He's one of the caste. And maybe he has family ties or links with some big fish. If he's the most important actor of his age, it wouldn't be a shock to learn he knows Wolff or Jason or else. And those guys seems to kill to protect their secrets.