Simulating real world transformer with LTSpice
Yes, that's correct. All other things being equal, inductance is proportional to the square of the number of turns in an inductor. Your inductance ratio is 50/.15 = 333.3, so the turns ratio is the square root of that, or 18.26. This makes your output voltage 18.26 &times; 12V = 219V.

Depending on their size, real transformers would have values about 1/10 to 1/100 of what you used, but for modeling purposes, it isn't all that critical.

The other transformer parameters are very dependent on the physical design of the transformer, and different designs are used to optimize certain parameters for particular applications. Coupling coefficient might be sacrificed for high isolation, fine wire might be used to get a lower magnetizing current, at the expense of increased series resistance, etc.