Am in dash but to fill you in on a few things briefly.
Indeed, no known contact after Friday. Most evidence points to her being killed and dumped around that time, but if that is not the case then of course interesting possibilities arise.
Boyfriend's alibi for the time you mention not necessarily verified as such, but not disputed. Police sources suggest that transactions at petrol stations etc corroborate the thrust of his claim that he was out of the area at the time you mention, although we don't have details.
The quarry area is actually one of the first non-built-up patches somebody would get to if driving somewhat randomly out of Bristol. But I think it may be relevant that it's in the area of some of Clifton College's off-site playing grounds.
Depends what you mean by "attacked" really but there's no certainty over whether she voluntarily left flat and was strangled later, was abducted and strangled later or was strangled at the building.
There might be various reasons for moving the body. But, indeed, stranger killers very rarely do.
Thanks. Another point that has been raised is that people have said that they often walk in the area where she was found. Those people have said that if she was in that location even a day or two earlier, she would have been seen. That leaves the possibility that she was abducted, held for a few days, and then placed near the quarry. That would explain her abduction from the apartment, yet I have not read that she has been described as having injuries in addition to strangulation. Was there any additional information given about injuries?