Structures with only single bonds (alkanes) do not have resonance structures.This goes back to the concept that sp3 hybridized atoms do not participate in resonance. If you haven't already done so, I recommend watching the below video on resonance. Structures with a double bond/pi bond (alkenes) do have resonance structures. 

At 10:44 Melissa talks about how you can figure out what is typically up or down. You'll also see this explained again in the chair flip section at 16:14. 

Let me know if this makes sense now.

If a structure has the ability to rotate more it means it can move to a more stable projection and avoid steric strain when necessary. 

This is because there is no alpha proton available so the beta will be on the side that has the phenyl group and the alpha has to be on the side that will have an alpha proton. This is explained at timestamp 16:54. 

Yes that is correct.

Yes you can also draw it that way, there are multiple ways to draw the same structure. You will see this concept further explained once you get to Constitutional isomers (structural isomers). For now you can see that if the structure is valid meaning it obeys the octet rule, carbon has 4 bonds etc then you can count the number of carbons and hydrogens to double check that it is another possible way of drawing the same structure. 

Stephanie McKinnon at timestamp 7:06 you'll find the halogenation mechanism and examples. 

There's no ether because that Oxygen is directly connected to the C=O (carbonyl group) which makes it an ester. For there to be an ether, the Oxygen would have to connected to 2 carbon chains that do not have any C=O. Attached you'll find examples of what an ether would look like if it were in the structure of practice problem 1.

Recall that there are different variations of amines some with 2 Hydrogens, 1 hydrogen or no hydrogens. This was shown at timestamp 13:10 

Yes, I just tagged you in a comment on the practice exam video.