but I’d love the rental income to cover the mortgage (after tax). .
This is impossible. It would be a great situation but it is impossible.
Is this because the rental potential of such a place in not likely to cover the mortgage? Please explain why?
1) Community fees are quite high. 100+ Euros per month.
2) REntals are low. In Torrevieja that you mentioned there are 1000s of properties for rent. Some of them give less than £1000/year i.e. less than community fees (let alone cost of utilities plus tear and wear).
Save more money and buy a better property without expecting it to yield any income.