What ways are there to hire freelancers for code, without them "owning" the code on their pc? And how likely is it with paid freelancers, that the game wont get to the release?

Development Programming & Scripting
2

Try to make a feature compelte tic-tac-to game on your own and you’ll get a taste of how complicated making a game gets, and why experienced leadership/management is essential.

If you offered me $100k to make a game at orders from somebody who knows nothing about it, I’d turn it down unless all the money was up front.

You don’t have to be the most experienced expert, but you have to have proven leadership skills plus you have to know a good deal about the domain.