Me too. I'm curious about what she did that was both so sensitive it couldn't be talked about yet was so unimportant it made no difference to the investigation.i would love to know what they found out about SLP. AS kept it out of his book, but i have always been curious about what she did.
We can infer a bit though, I think. There are clues. In terms of things said, her parents were quite churchy and observed that she "did not live her life as [they] would have done"; AS said the omitted material was "more News of the World"; and all the police would say was that she 'was a modern young woman'.
I think we can eliminate drug dealing or most other forms of crime as too critical a line of inquiry not to have leaked out. Casual drug use seems quite possible though. She smoked cigarettes, so may have smoked other things and this could still be consistent with that police choice of words.
It seems unlikely she was on the game. Someone would have known, it would have leaked, and I doubt the police would have characterised being actually on the game as normal for "a modern young woman".
When the parents tried to protect her "reputation" it seems most likely to me that it was her sexual reputation they meant. If all she had done was sleep successively with each of her blokes in the usual way, the parents would regard that as shameful, but the police might well say it was just "modern" and if that's all she did, AS would hardly have described this as "News of the World" material.
So whatever it was went beyond that. A propos, I note that she was adept at keeping her social contacts segregated, she even had a secret diary nobody knew about, and AS has her either three- or possibly four-timing AL when she disappeared.
Taken together, I would guess that the stuff removed possibly related to prior drug use, perhaps among the QE2 crowd, the wealthy West End crowd or both; and in addition she probably had a body count at the high end of normal, and a rapid turnover.
The police would consider all of that within the normal bounds of modern women's behaviour, it would dismay her parents, AS would agree the combination of it all took it into News of the World territory ("Suzy's sex and drug orgies shame aboard QE2"), and if it came out, it would be adverse to public co-operation. In short it would fit all the hints dropped, and it would suit everyone for it not to emerge.