Quote Originally Posted by greenmark:
1) the 15% tax on dividends is withheld at source.

2)Deemed Disposal is a tax on ETFs that applies to residents of Ireland.

3) If resident in the UK then you pay CGT on your worldwide capital gains. You pay them in the tax year that you realise those gains. If you realise those gains before becoming UK tax resident then you don't need to pay CGT to the UK. You need to be non resident for a minimum of 5 years though. And any property investments are still liable to CGT.
This is basically the answer, thanks @greenmark.

Just to add a few things:

- The 15% tax on dividends only applies to US stocks, not any other stocks.
- UK taxes only applies if you are UK tax resident. If you are not UK tax resident, then you only have to concern yourself with HK taxes (of which there are no capital gains taxes).
- If you move back to the UK the present advice is to sell your assets first and then re-buy when you are back in the UK.