It doesn't disregard on screen dialogue and events. Because our characters still have money. That's including Jeanluc Picard, dr. Crusher, and Harry Kim. In a society without money, you won't have any money / currency because you don't have any income.
But that's work if only Earth that free all the people from paying anything. AKA, they don't need to use money to fulfill their daily necessity. In First Contact, Picard said to the woman that there is no money in 24th century. But the context was the 24th Century Earth.
While Jack Sisko spent his childhood in USS Saratoga before he moved to Utopia Planetary Ship Yard with his father. He is virtually lived in Starfleet Facilities in his early day (before he moved to DS9). So it's make sense if he doesn't know money.
As long as I know, there were only two characters who mentioned that Earth doesn't use money in Star Trek. And the context is Earth.
You're right about Science fiction is meant to imagine these things. But still, these imagination should be making sense. The problem is that Harry Kim collecting coin, Riker stashed latinum, people don't work and just doing their hobby was actually doesn't make any sense at all. That's why I said that you should explain your argument with our current economy model as the basis. Not just Harry has the hobby to collect money, Riker love to stash latinum that we don't even know where he got from, etc.
Ok, Federation doesn't use money. So how their economy work? Abundant energy reserve, or Unlimited Energy Income like what you said? Abundant is making sense, but unlimited energy income is a NO. Because there is always a limit for everything. And there where is the energy come from? Your explanation doesn't explain everything. Right now, we use nuclear, solar, geo thermal, hydro power, fossil fuel, etc. Still they are not enough to fulfill the energy needs for 6 billions people on Earth. So what happen if they need to fulfill the energy demand of 8000 star systems with thousands of billion people energy need? Then what will happen if there is uncontrolled urbanization / movement; from other civilizations to the Federation Space? If the Federation Energy Reserve can fulfill the need 8000 billion people, then what happen if the number of people raise dramatically? Say 100.000 billion people? That will nullify the abundant energy reserve and reset everything to our current situation again.
And the funny thing is that you said that every planet is self sufficient, and thus eliminated the need of trade. Then why Star Trek Insurrection was happen? Why the Admiral need to move the people of Baku from the planet just because they need the substance in that planet for healing property?The replicator can't replicate that substance?
Then it's become funnier when you said that people don't need to work because of replicator. They just do that for hobby. That kind of society would drive our Earth to this state of event :
http://www.imdb.com/title/tt0387808/