Hello,
Can it play the contents of a USB flash drive? (movies)
Thanks in advance.

Most likely your DVD player will have an hdmi output you can use.
The usb is there to connect a memory stick.

I tried that too and it didn't work. You would have to connect a laptop with a drive (internal/external) via HDMI.
Or you can rip your DVDs and then save the files on a USB stick or external hard disc.