Hi, everyone I'm back (it's been a while).

So since I am home from college I finally get a try at figuring out what happened to my car when it died almost a year ago.

Let me take you back to last year to give you an idea of how the car died.
I had just recently replaced the clutch (It was quite pricey and the mechanic had no idea what he was doing and wound up also replacing the starter as well as the wiring harness) and the car was back to operating. One day as I was driving the car home from college I noticed smoke coming from the hood, and by the time I had pulled of the road the car had already died. I looked under the hood and low and behold there was no radiator fluid. I had some water in my car and filled up the radiator. I managed to get the car home by filling up the radiator with more (cold) water every few miles. By the time the car made it home there was a large hole on the top of the radiator. I replaced the radiator and filled it with coolant, I also replaced a leaky hose that I believed was the reason why the car ran out of radiator fluid in the first place. I drove the car for a few days until it started having problems starting. After much investigation it turns out that the car was practically running on no engine oil (Perhaps the oil burnt up when the engine overheated when I ran out of coolant?). I refilled the car with new oil. The car drove another few hundred feet, and then refused to start... period. That was over a year ago.

Back to the present.
I had figured that I had probably cracked the engine block or at least the head gasket when the car overheated (probably twice). This was confirmed when I found oil (looks like oil) in the coolant overflow reservoir. To convince myself that I had a serious problem I decided to drain all the motor oil and see if it had water (coolant) in it (keep in mind the car was only driven briefly with the new oil, although it sat for over a year afterward).
Surprisingly the oil looked water free!

The questions.
1) Does oil in the coolant but no coolant in the oil indicate something?
2) Is there an easy way to determine if the head gasket is blown, or the engine block, or both?
3) is replacing the head gasket difficult and/or expensive?
4) Any other advice/insight would we greatly appreciated.

Thanks a million!!