With the way it ripped up the ground, it looked like that landing pad hasn't been used in a long time.
Certainly long enough that nobody (save the droids) even knew it was there. But that's not a surprise; even if the planet "only" dates back to the High Republic, that's still several centuries at this point. Plenty of time for it to get completely overgrown and turned into a green space. If it's from the
Old Republic, then that's an order of magnitude more credible!
I mean, why berate the children when there was no reason to?
He had a headache. Also this is hardly the first time he's expressed frustration with home much trouble the kids are causing him, and now he can vent without consequence, because he doesn't need them anymore.
As for the "heart of gold" thing; I think people just assumed that would be his arc going in, but looking at it objectively; almost nothing he's said or done really supports that. There may have been a few glimmers of honesty and some semblance of kindness here and there, but it was always in service of his own goals. He never once willingly compromised his chances of self-enrichment for the sake of those kids.
I'm wondering what his play is at the end of the episode. The parents and kids aren't armed, but there were plenty of security droids all around them that are, so going on the attack (or even threatening an attack) probably wouldn't end well for him.
I assume Plan A is: "get the barrier down and have the crew plunder the vaults of every last datarie", while Plan B is likely: "load up as much loot as he can onto the Cinder, and flee."
As for At Attin's defences; A bunch of walking security camera and nanny droids armed with stun-sticks won't do much against a horde of blood thirsty pirates with blaster, fighters, and ship-mounted cannons. We've also been shown twice now that they have ion-weapons for dealing with droids.
Even then; those droids couldn't even stop a bunch of bumbling mid-level bureaucrats from breaching the barrier with an improvised com-relay.
Only Neel knows the planet may have more teeth than Jod is expecting.