I think you're probably imagining life in high society after watching everything Julian Fellowes has written.

Victorian prudishness is somewhat a myth. Not like completely, ofc, but way overblown.

If you'd make your argument just for Victorian high society, I might be inclined to agree. If you make it also for the middle classes, I'll be skeptical. And if you argue that the working classes would've all shared in those strict morals, then I'll disagree.

Although I'd like to point out that those Victorian high society or upper-middle class people, especially women, would've been de facto under surveillance most of the time, constantly having other people or at least servants around watching them.

But like we know from Downton Abbbey and the Gilded Age etc, they found ways around it as well. To answer your question about breaking the law or being embarrassed, being embarrassed would be why getting in trouble with the law would be troublesome and being embarrassed might mean being thrown out of society, which would be way worse than having to pay some fines.

Ooh I think there's a new gilded age episode today btw