higher earner status for savings allowance

Assuming my total taxable income is £38k (after the standard allowance has been deducted), and this includes £1k interest from savings: 1. Would I only receive £500 of the personal savings allowance (as a higher earner) instead of the full £1,000, even though I would not be paying any tax at the higher 40% rate after this £500 is deducted? 2. If I made a £1k private pension contribution (after tax) in that year, would that affect whether I am classified as a higher earner and increase my personal savings allowance? 3. What if it were a £1k Gift Aid donation instead?

Hi,
We cannot comment on scenarios or examples, we can only provide general information and guidance in this forum.  
For an answer to a detailed question of this nature, you would need to seek professional advice.
Thank you.