Spanish mortgage floor clause

Not sure if this is correct forum but looking for advice on a mortgage with Spanish bank. Have a floor clause of 4% which I have asked my bank to remove. They have offered to remove it if I take out life insurance or open savings account and put 30 pm in for a year. Can cancel it then. So currently paying 5.3%. If it is removed would be paying 1.3 or eurobar plus0.3. Mortage started in march 2008 and will end in march 2033. No refund of any overpayment.

Would appreciate if someone could work the figures for me - what have I overpaid - is it worth pursuing?
What would I be paying going forward currently 520.80 pm?
Basically should I go for it?