Do I have to warp it in any way to throw it as a left-handed boomer?

Aerobie Orbiter High Performance Boomerangs are designed to be thrown with either hand- they don't discriminate :) Simply throw it as the package suggests and righty's or lefty's are sure to have a good time!

How do you get this to return? Following the directions isn’t working.

There is a good Utube video by the inventor and He give a good demonstration how to throw it. He points out that it can only return if you throw it right-handed..it should say that on the box...I found that when the orbiter was made in the USA it was a much better product. The ones made here in the USA just flew farther and easier to control.The ones made in China don't fly as well and land short.I own 6 USA orbiters and 4 Chinese models even though both products look identical they're not.

Picture shows made in usa but made in china?

I haven't found an aerobie orbiter made in the USA... originally they were manufactured in Pala Alto CA...now they are all made in China. It's a shame I purchased 3 of these Chinese models and they don't fly as well as the ones made in the USA...

Does that hook affect left-right orientation?

Not sure what you mean by the hook...the orbiter wil return to you with wind conditions about 5 to 7mph. The box should say lefthanders will have a difficult time making it return and should be encouraged to used the other arm I did ..The product was a lot better when they were made in the USA. The Chinese orbiter demands a lot of tweeting to get to return.