Law Firms in UK and HK

There are lots of UK law firms that has an office in hk.
eg. Allen & Overy, Bird & Bird, Baker McKenzie, Clifford Chance, Herbert Smith, Linklaters, Lovells, Richards Butler, Simmons & Simmons, Slaughter & May etc etc.
As far as I know:
1. if you get into one of those as a trainee, there is some chance when you will be working as a posting in hong kong for a few months. but this is only part of the articled clerk program and you do not get to stay in hk afterwards.
2. if you are employed as a solicitor in uk, usually you would not be transferred to hk unless you are exceptionally good in a certain field that is not found in hk / or there is a demand for an overseas posting. the branch in hk engages their own staff from hk anyway and there really is no need for an internal transfer from the uk.
3. even if you are transferred you would be treated as having a contract with the hk branch so you would be drawing a salary from the hk office - not the uk office.
4. usually international transfers only happen at partners level.
5. now that hk is back to being part of china, having a british passport does not mean you can automatically work in hk. you still have to go through the normal process of applying for an employment visa. but being a solicitor i do not think that would be a problem.