So the mom basically strong-arms Owen Wilson into giving her $100k so the latter can train her son and accompany him to tournaments. Then after basically bankrupting Owen with her insane demands, she still has the gall to whine about not wanting to slum it in a RV to save money but instead wants a hotel room, yet doesn't get herself one with her newfound wealth, but gets the guys to put her up after complaining a bunch. If anything, she should be the one paying a retired pro for the opportunity to train her son, but instead she gets freerolled every step of the way.
Santi is just a kid so some of his behavior can probably be blamed on that, but the entire "I love playing golf and want to be the best" and "uh, oh, thing's aren't going my way, better throw a hissy fit and run away" dichotomy was pretty annoying. Either you want to play so get with the program or you don't so pack it up. Him going between these two extremes was definitely one of the most annoying parts of the entire season. Especially considering he's being handed everything on a silver platter yet he still sandbags the entire operation.
Zero, well, I have no idea what the writers were thinking there, but listening to the lines she delivers, especially in the first couple of episodes she's in, the writer's must've fed an AI prompt like "generate me random lines that have the highest probability of riling up the anti-woke crowd". Also the fact that she's old enough to tend bar, meaning she's at least 21 and is banging a 17 year old is kind of weird.

Mia picking up a would be victim in a bar and bringing him back to her place, without that being potentially disastrous in terms of arrest, followed by Harrison not seeming to wonder how Dexter happened to know the address of an at large serial killer