Please refer to the following link in respect of claiming the property income allowance:
Tax-free allowances on property and trading income
If your total expenses are more than £1000 then it will be more beneficial for you to claim the actual expenses incurred instead of the Property Income Allowance.
In respect of the residential finance costs you would still enter the figure of £232 in Box 43.
As of the 2020-21 tax year you will no longer deduct your finance costs from your profits as an expense but you will instead receive a basic rate tax deduction in respect of the finance costs incurred. This will automatically be shown in your tax calculation for the year.