MicroSD Card speed + Booting from USB

Hi,

I read some Speed tests about MicroSD-Cards. And they showed very slow reading / writing values.
The technical data from the cards shows more faster values as the test results are.

1.So what is the problem from the raspberry for that bad results?
2.Is it possible to boot over USB my OS so that it goes faster over USB3.0?
3.Is it possible to create a 2nd partition on the SD Card, so I can use it as ntfs partition to safe movies there
…and use it on my windows notebook
…or on my NAS-Server
4.Is it possible to download movies directly on an USB stick and use this normally on my windows pc?