As far as actual confirmed stuff goes, the DBZ Moon is the real Moon. Piccolo is a moon destroyer. There aren't any anti feats to suggest otherwise.
The Daizenshuu states that the Kamehameha is able to "shatter even the Moon". Even if you consider the entry to be merely talking about Master Roshi's outlier feat, that shows his feat is considered way more impressive than what Piccolo did in the 23rd TB, therefore one can't use the "King Piccolo destroying a city is regarded as a more impressive feat" argument (which is already relatively thin because feats don't scale to each other at all)
Raditz has no feats to suggest he could planet bust, so we can't say that.
Nappa's ki blast did not even damage his space pod (which was easily destroyed by an enraged Gohan whose PL was 1,300) in the slightest despite the fact it destroyed a continent sized area. He can control his ki's destructive capacity.