CGT on foreign property around the time of a move to UK

I left the UK 10 years ago and currently I live abroad in a home purchased for me by my parents (who also live abroad). This has been our principal residence. We need to sell this home and buy one in the UK ahead of a planned relocation to UK in Q3 2025. (i) we may visit UK for brief periods (1 or 2 weeks at a stretch) in order to search for a property prior to our actual relocation. How does HMRC determine the actual date upon which we relocate? is it the date of our removals company / the date our family travel to UK with no return ticket? (ii) if we sell our foreign property at any date prior to our relocation to UK (even the day before), will UK CGT be due on the foreign property sale? (iii) if we relocate to the UK before we are able to sell our foreign home, and it only sells after we relocate, do we have to pay CGT even though it was only ever our principal residence? (iv) if we end up buying our UK home (intended as our principal residence) before we sell our foreign home, then for the purpose of UK stamp duty, does the UK purchase count as our first home, or does the foreign property make it the higher second-home stamp duty rate?

Hi,
It is the date of arrival in the UK of the individual that is used when working out your tax residence status.  
Each of you will need to review the statutory residence guidance at:
RDR3 Statutory Residence Test, to work out your residence position.  
If you dispose of the foreign property in a UK tax year in which you are not resident, there is no capital gains tax liability.  
If you are UK resident at the time of disposal, you will be required to declare the disposal in a self assessment tax return.  
There is a calculator at:
Tax when you sell your home to help you work this out using UK capital gains tax rules.  
As this is you main residence, you can claim private residence relief for the period of ownership that the property was your main residence:
HS283 Private Residence Relief (2024)
All figues must be in pounds sterling before the calculation begins.  
Under the terms of Self Assessment, we do not provide an official exchange rate and the onus is on the individual to use a just and reasonable exchange rate for each acquisition and disposal.  
For your convenience, there are exchange rates at:
National Archives
Exchange rates from HMRC in CSV and XML format and for older rates at:
National Archives
Exchange rates from HMRC in CSV and XML format
You are free to use any of the supplied rates or one of your own choosing.
Thankyou.