Hi Ken,
You´re right: SiteGround approach it´s quite disappointing; now as you said I´m 'between a rock and a hard place'.
Finally, I guess that my only option to install Moodle from scratch with them and rewrite all my courses (fortunately they don´t have much content yet).
The process of going from localhost to a remote server it´s been so frustrating since before contacting SiteGround I spent a couple of weeks trying to migrate my courses to a free hosting site with no success... It was even harder. The lesson I´ve learnt, and I hope it may be useful for other users, it is that if you want to practice with an experimental Moodle course it is better to start it in a free hosting remote server from the very beginning. Migration process it is a real pain.
Thanks for your help and I´ll inform you about how things work.
Take care and a big applause for you.
Pablo