"For formal nights on the Golden, is there a place for nice dancing?"
I'm not sure what you mean by "nice dancing," but there are two dancing venues aboard each of Princess's ships.
>> The Wheelhouse Bar, or an equivalent lounge on Princess's older ships, has two combos that play live music for your dancing and listening pleasure from 5:00 PM until 1:00 AM or thereabouts for dancing. It has been my experience that one of these bands usually is outstanding and that the other might not be as talented.
>> The disco (yes, literally....) cranks up around 10:00 or 11:00 each evening and continues well into the wee hours if that's your style. It's not exactly my style.
I have not been aboard MV Golden Princess, but the wheelhouse bar appears to have the same dimensions and layout as aboard MV Grand Princess. I found the Wheelhouse Bar aboard MV Grand Princess to be much too small for the size of the vessel. Thus, it's apt to be crowded, especially if you try to go there after dinner or after the show. Princess really need to shut down Sabatini's Trattoria and use the space to enlarge the Wheelhouse Bar.
If it's not too late to modify your plans, I recommend booking aboard MV Sun Princess, MV Dawn Princess, MV Sea Princess, or MV Ocean Princess instead -- especially if you like to dance. The Wheelhouse Bar aboard each of these ships is considerably larger than aboard MV Grand Princess, so there's plenty of room. If you prefer the disco, it is in a much more convenient location (amidships on the Promenade Deck) than aboard MV Grand Princess (on a deck by itself in the "spoiler" over the stern).
Have a great cruise, whichever you decide!