Colingu

I am a non-UK resident having been out of the UK for the entire tax year, but still a UK citizen. If my only UK based income is less than £1000 from interest/shares only, do I need to file a self assessment (SA)? I have filed SA for all previous years. If I don't need to file a SA, do I only need to tell HMRC via filling in the online form? Do I need to claim my allowances using a R43?

Our self assessment refunds showed as "Repayment Pending" yesterday and today changed to "Bank Repayment Pending". What is the difference? What is the time-frame for the money to hit our bank account?