Question about transformer reflected source
That's an excellent question - it really gets to the heart of how transformers work.

If the load is infinite (open circuit), and the transformer is ideal, no current will flow in the primary. (If you try it with a real transformer, you'll find a small current flows, but way less than you would expect from just considering the primary as an inductor).

If the load is 0 (short circuit), and the transformer is ideal, the primary will act like a short.

Here's a good explanation of why this is true (hint: it's all because of back EMFs): http://www.physics.usyd.edu.au/~khachan/PTF/Transformer%20explanation.pdf