Do not worry about camera shakiness- trust me, we all have that problem. It is hard to video tape this stuff and we know that!
Try to pay attention to her sneezing if it continues. Some dogs actually alert a scent trail this way. It can also be they are expelling air from their nostrils to clear it of unwanted odor as they search (I think that is what is happening here). So I will be curious to see if this continues. Her searching behaviors are fantastic, and you are doing an excellent job of letting her work. She is one determined gal!
What you have her doing in Part 2 is actually pretty advanced as indoor hides go, as it is such a large area she is working. I am very impressed! Also excellent work on having her drop it after she finds it. Practice has paid off
PS I only saw part 2 of 3- the others seems to be the same link to part 2! Not the end of the world, I see lots of good things- when you have time- do post the other ones though so we can see.