Is there any scheme by EU countries for highly skilled workers to apply for temporary residence permit without having a job offer?
I think the US equivalent is O Visa, as someone can get a temporary residence merely based on his qualifications and work history; then trying to find a job when residing in the target country.
I want to move to a country then try to find a job through small projects with local businesses.
Having a work contract or binding offer is a strict requirement for the EU blue card, see article 5(1)(a) of the Blue card directive. There is even a minimum salary requirement. So the Blue card is definitely out.
What's left are therefore the national visas/residence permits and the rules differ widely from country to country, you need to be a little more specific about your situation and destination to find out what's available.
