Any of the cameras you mentioned will fill your needs.

I have not seen any reports about noise levels for the Panasonic FZ7. But the previous FZ5 camera had more noise that the other cameras you listed.

All of these cameras have the necessary manual controls that will let you expand your knowledge of photography.

Are expensive cameras "worth it"?
If you are interested in photography...yes.
If you want to take photos and not worry about a lot of buttons and such.....no.

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