Underage blowjob

1, 2, 4, 5 and 7 He's showing moral character as Reds says.

😎

6-He did not know exactly where that mouth had been, but had a pretty good idea.

Think about how often in the film Cliff Booth is contrasted with Roman Polanski. It’s quite often. The scene is there to show us what a real man would do and what a worm like Polanski would do in the future.

Everyone here is making this damn complicated.

The scene just shows us how "simple" Cliff's character is.
He's a simple person. Practical. Pragmatic, as someone else put it.
It's not about morality. It's about simplicity, and keeping things as simple as possible.

Underage blowjob. Illegal. Won't do it..because it could make the situation more complicated, having to avoid the law.

Another example...3 intruders in the house. Got a guard dog.
Use the dog to attack all of 'em.
That's simple.

This contrasts with Rick's character, who makes his own situation more complicated than it actually is.
Hell, much of the film's energy is centered around the drama Rick creates for himself by wallowing in the past and trying to move on.
This contrast between complexity and simplicity is what makes the chemistry between Rick and Cliff's character so interesting.

why post this junk?

I think moral issues and also he doesn't wanna go to jail.. mostly the last one.

Although his character is apparently quite good, except for the wifey but I don't think he killed her TBH

I think it's a combination of 1,2, and 4 on your list (1 & 4 are basically the same btw) I interpreted that he did have some attraction towards her based as on multiple occasions he sees her while driving, engages with her in long flirtatious smiling and waving but was "put off" in a way by how easily she offered him oral sex , and responding in a truly surprised manner "Nobody ever asked me that before" after he asked about her age suggesting she probably offers to blow most guys who give her rides.

So Cliff's declining the offer I think boiled down to her possibly being underage "No poontang is worth going to the big house over) and he likely considered himself "above" the weaker, more desperate kind of men she has encountered who would readily accept cheap sexual favors (No questions asked) from a cute hippie girl who probably gives them out like candy.

Goodness, I didn't know we had so many puritans on moviechat. lol...

If you re-watch the entire scene, I would have to say the answer is #2. He just doesn't want to get arrested for doing it with someone that's underage. No morals clause in my view. But I am a bit taken aback by the choice of words in your OP, Heisenberg. Are we to believe that "any" girl that offers sex to a guy that happens to be older than she is is a "skank" or a "trashy little girl", or would that be just a Manson girl? You might need to clarify this one. I never quite understood this line of thinking that some males have from time to time.

Any man that would view this girl as a "skank" is ignorant. Not to mention, it's a really old way of viewing sexuality. It's usually just puritans or hardcore religious nuts that think like this...

It was kind of funny how Cliff was viewing her in a somewhat sexual manner when he saw her on the side of the road but turned her down when she offered it. This is just something you see in movies. Guys don't turn girls down unless they just don't want to get arrested. Plus, I'm not sure what the age of consent laws were back in the 60s. I doubt they were as harsh as they are today. Not likely he would have gone to jail for just getting a BJ from her.

However, I can see Cliff proceeding carefully after Pussycat tells him where she's living. Once Cliff knows this girl is living at Spahn Ranch, he made the decision to become a "detective" and try to find out what's going on there. The fact that he used to work there made him curious. So, this could have also influenced his decision to turn her down but nothing in the movie says he thought she was a "skank" or that QT was taking a jab at Polanski.