To start with, I'd scan it for codes again to see what pops up.
So, did you have the shop replace the radiator and the other leaky parts? It's possible coolant got onto the alternator and caused it to fail. A failed alternator can cause the battery to lose its charge. Also, a failed alternator could make the car fail to start if it is draining power rather than providing power. I'd pull the alternator and have it tested.
You did say you have misfires. Did the shop address that issue? For starters, a good coil pack, plugs, and wires are needed to get the engine to run.
Other than that, an engine needs air, fuel, and spark to run. It sounds like you're reasonably sure that it's got fuel, so I'd pursue the lack of spark theories above.
So, did you have the shop replace the radiator and the other leaky parts? It's possible coolant got onto the alternator and caused it to fail. A failed alternator can cause the battery to lose its charge. Also, a failed alternator could make the car fail to start if it is draining power rather than providing power. I'd pull the alternator and have it tested.
You did say you have misfires. Did the shop address that issue? For starters, a good coil pack, plugs, and wires are needed to get the engine to run.
Other than that, an engine needs air, fuel, and spark to run. It sounds like you're reasonably sure that it's got fuel, so I'd pursue the lack of spark theories above.