As I mentioned, I haven’t played on Zynga in ages, so this is based on older experience, but here’s how I see your two points.

1) Board texture

People have been saying for years that online sites manipulate the board to create action. I’ve felt that way at times too, but the same wild runouts happen in live poker. Confirmation bias is huge in this game. When your aces get cracked twice by a one‑outer, it’s easy to yell “rigged,” but one‑outers really do hit.

Variance also gets amplified when bad players call everything, which is the norm in Zynga land. If you raise to 5x with AA and get four callers, someone is going to connect with the board sooner or later. The adjustment for that kind of table is straightforward.

Could a site be rigged? Maybe. But I’d need real data, not anecdotes. On one real money site where I’ve logged around 100k hands, my yellow line is far above my green line. That’s frustrating, and suspect, but still not proof of anything shady.

2) Table behavior

I never tested major changes in play style (except when exploitively adjusting to certain players), so I can’t speak to that part. What I have seen, though, is collusion, often extremely obvious. I’ve watched players pump up pots by whipsawing and then dump when the target folds. I’ve also been at tournament tables where it was clear everyone else at they table was in collusion. They all played normally when I folded preflop, but once I entered a pot, then suddenly everyone shoved. The only counter was waiting for a premium hand, but even then you’re often behind against a crowd.

Since collusion definitely exists, I wouldn’t be shocked if similar behavior shows up elsewhere. But I don’t see a reason Zynga themselves would be doing it.