All those things I said stop them from fleeing? I'm not sure I understand the question. Yes, you can flee, but you're going to spend the rest of your life as a wanted criminal. It's not exactly easy.
Letting people go home without bail would include the same risk of fleeing, without the additional financial incentive. So, if the concern is people skipping trial, how does that help?
Not a lawyer, but I believe police are supposed to collect evidence before they make an arrest, to provide justification for the arrest. If there are places they still need to search, they can probably lock them off, but I think most of the evidence should already be in police custody.