Hey all, a bit of a story here but could really use some help! I've done a fair amount of research, however don't know a lot about cars to begin with.
I stumbled across this forum which appears to have many knowledgeable users, so thought I'd try to get some input. Any suggestions are appreciated.

A couple months ago I started noticing a brown/orange stain underneath my car. I figured this to be old rusty coolant, related to a potential radiator leak, so decided to get it looked at.
The mechanic replaced the water pump, and performed a coolant flush to try and rid some of the rust. I was told it was still very rusty, however, after the flush.
I was recommended to replace the the cooling system hoses (radiator and heater hoses), thermostat, and radiator in the near future.
I planned on doing these things as soon as I saved up a bit more money. In the mean time, I tried to be mindful of these issues and drive a minimal amount.

A little while later, my girlfriend was driving the car when white smoke started coming out from under the hood. She also said it smelt like antifreeze. At this point, I assumed it had overheated. We had it towed to the nearest shop, where they said it was most likely a cracked head gasket or cylinder head. I got the car towed back to my house where it has been sitting (legally) on the street (I don't have a garage).

I planned on doing the research and fixing the issues myself as a fun project and a way to learn more about cars as soon as the weather got warmer. Over the time it sat on the street (again, legally and with no complaints), someone broke in and attempted to steal the car. The ignition cylinder was pulled out and the small silver tab broken off. Correct me if I'm wrong, but this tab is spring loaded and purely meant to keep the cylinder in its housing, therefore should not affect starting? If this is true, I should be able to stick it back in and start the car with the key. I tried this to no avail. No sound, click, or anything. I then tried pulling it back out and starting with a screwdriver, which I'm guessing is what the thief tried so wouldn't work either. It didn't. I then tried starting with the car in neutral to bypass the NSS. Nothing. This is where I'm at now.

I still would like to fix the car once its warm outside, however, don't know where to start now. Despite possibly having a cracked cylinder head, the vehicle should still start, correct? I have not driven nor turned the car on since it was towed after my girlfriend was driving when it started to smoke.
The battery and terminals are good. The next thing I was going to check is the starter, then bypassing the ignition switch, which would essentially mean hot-wiring the car. Is this worth investigating? What's the best/easiest way to accomplish this without cutting wires?

Once the car can start, I will start working on the other issues. Any suggestions on how to go about determining what all actually needs fixing/replacing? Here are my thoughts:
1. Check the head gasket for cracks and replace if necessary.
2. Check the cylinder head for cracks and replace if necessary. How should I go about this? Pressure test? Powder test?
3. Replace all coolant system hoses to fully get rid of all rust.
4. Replace radiator.
5. Replace thermostat.

I know this was a lot, and like I said, I don't know too much about cars so any help is very much appreciated! Thanks for reading.

Here is an image of the tab on the ignition lock cylinder that was broken: