rtl-sdr.com

good to hear. I use Ubuntu too.

can you try something a little older like 3.7.10 ??

With the Gnuradio app up and running. Do a cntrl f ....opens a search field a the top of the block section on the right . Search for rtl.

Things look proper, documentation looks good. Haven't used Kali before.

Just 2 off the wall ideas.

Do you really have to be root?
try using the rtl dongle on a powered hub.

Yes, continue That looks correct

The PLL not locked is normal for all of us.

That circular button to the right of the selector is a refresh button. Refresh the list. You may already know.
If not , it may be the device your expecting to see is already in use.

I've not used this RDS plugin before and I usually don't use plugin managers, so I'm probably not going to be of help. I will say that what I've seen about the RDS plugin is that it's 4-5 years old and sdr# has evolved whereby older plugins no longer work. There's a big change around ver 1500. I thi...

I don't think it's a plugin...it just comes with WFM.
What's that circular object below the RDS stuff?

I would install gnuradio companion and gqrx. Then run volk_profile...after that run gqrx. It's a radio app.
Or you can try the suite of apps that came with rtl_test....like rtl_fm ...etc