Well, where do I begin......
This has nothing to do with Spain, but just relocating to a foreign country. I have just gone through one of the most horrendous years of my life doing it....
Everything that annoyed you here will annoy you more out there... You can't speak the language, the laws are different and hard to pin down. You are far away from you usual support network, supplies aren't necessarily easy to come by... Nothing goes by the speed you are used to... If you have banked on having £10K to see you through the transition, then multiply it by at least 4... If you though it would be £50k then same goes.
For 6 months my life was a constant trial, I went to local government offices day after day after day...
All the problems you have here starting a new business are multiplied... Are you targeting locals, tourists or ex-pats? There is a business out there already for all of them.... You have to be good, you have to be unique, you have to give them something DIFFERENT! If that's speed, quality, whatever, you have to offer them SOMETHING!
So I sound very negative??? Not at all!!! I love my life here, I love my business, it's a joy everyday that everyone I meet is different! I would not change one tiny thing for the world!
Go into it with your eyes open, expect the unexpected, go with the flow when needs be, and you can have a very good and happy life, doing the job you enjoy in a beautiful country! All the luck in the world to you x