Visas situations will change almost certainly in 10 years. Spain has some digital nomad visa but you never know how long will they last given a lot of countries are now voting in politicians actively challenging immigration. If you move because of politics, do something to change politics home, situation is not much better in Europe (and Spain and their mess is a special case of fun as well). Europe is not some kind of wonderland where you’ll be able to live cheaply, cost of living is pretty crippling for many individuals here as well. Highly recommend checking what happens in economical powerhouses of Europe like Germany, Nerherlands and France, their political situation projects to poorer EU countries.
Typically you need a business in EU and pay taxes in EU to be able to live there.
Btw worth checking the map, Seville is not on the coast (and this is EU vs Us perception of distance, 100km from the coast is not at the coast here). It’s by now a semi-desert location with crippling heat waves in summer.
Funny, I never had to watch my back where I live in Europe and my nearest shop is 5 minutes walk. Megacities in Asia freaked me out as this impersonal places of no soul. I never got feeling of safety there.