Hi isa,
1. For working out any gain, please refer to guidance at
HS283 Private Residence Relief (2023).
2. If claiming split year and your start date in the UK is after 30/11/22 when the property was sold, there would be no UK CGT to pay
3a. the capital (loan) is not taxable
3b. yes any interest received is included in your taxable income, it will be all the interest and not just 50% as the account is in your name
irrespective of how the funds were placed there.
Thank you.