Took a little to figure out where the crack was, top picture is such a close-up I could not tell what you were pointing to in it. Unless I'm not seeing right that is the casting for the front of the engine oil cooler. Only thing inside there would be coolant. That would explain why there was no coolant in the head or engine.
As for it preventing the engine from starting, well no but you should not run it till this is fixed as you must have a bad coolant leak there and to run it with no coolant in it will cause other problems fast.
I'm also having a bad feeling about this engine. To have a crack there and the nasty rust I saw inside the head makes me think this engine was run with straight water and left set that way and it froze. This crack maybe only the tip of the iceberg, pun fully intended. There may be other parts damaged from freezing. It might be worth filling it with coolant and let it set for a day if it will even hold it that long with this crack. Then open drain on crankcase to see if there is any coolant in there. Note that I said fill with COOLANT, that was for two reasons. First being I would not want to be responsible for damage from freezing again and also I feel coolant will actually leak faster that water and be easy to identify if it got to somewhere it should not be.
If you can assure this does not have any other leaks I will try to look up the part number for this cracked casting if you do want to replace it. Then once you get that fixed we can worry about why it has not started. If it becomes absolutely necessary to get it running before making further repairs we could do that but any possible damage will be your's and your's alone.
