Dende would have liked Freeza to become good

[SIAD]

I mean how the story would have been if Dende instead of transferring everyone except Goku and Freeza to Earth, had wished Freeza became good. How would the story have developed?

 

[Captain Cadaver]

It wouldn't be possible as Porunga can't surpass the power of his creator and, thus, can't alter Freeza just like how Shenron couldn't alter #17 and #18. It would also be pretty questionable how "good" that would make him when considering most of the Dragon Team are good yet flawed beings.

For the sake of the scenario, I'll assume altering Freeza's brain doesn't necessarily count as going against the rule and that Porunga takes it to the extreme and makes Freeza a paragon of good, essentially becoming a more serious version of Kuriza. Because Dende didn't wish everyone to go back to Earth, Freeza and Goku would go about getting as many people as they can on their individual ships, getting most of the newly revived inhabitants. The Grand Elder chooses to remain on Namek as he was fated to die anyway. Freeza apologises profusely to the Namekians and vows to protect leave them alone as well as make sure nobody else attempts to attack them. As the Grand Elder couldn't transfer his status over to Muri, it likely takes a while before Muri can create a new set of Dragon Balls, so the wishes involving the Namekian Dragon Balls happen a lot later. Goku doesn't go to Yardrat and instead returns to Earth, with Freeza agreeing to come spar with him after he's finished re-organising his empire into one of justice.
Of course, Cold isn't so keen on Freeza's sudden change of heart and confronts him, forcing Freeza to fight and defeat him to Freeza's dismay. Freeza then has him placed under the Galactic Patrol's custody as a prisoner after negotiating peace with them, finally having time to return to Earth and train with Goku at around the same time his Mecha self would've normally come to destroy both the planet and Goku.
When it comes to the training gains, this is where things get tricky. Obviously, you could have Freeza getting to God level in 4 months and Goku rivalling some Boo Arc characters like Tagoma did, but I'll say for the sake of this not automatically becoming a case of Freeza saves the day that the lack of his desire for vengeance, suffering in Hell or knowledge of Goku beating Boo lead to him not making absolutely incalculable gains in short time. He would still become far stronger, though not to the same extent; also providing Bulma with technology in which to contact him with should they ever need his help when he's governing his empire in space. When Goku contracts the heart virus, he rushes to Earth with his best doctors and medical equipment to save him, but is far too late.

He is again initially absent when #17 and #18 attack and likely takes months getting there. Vegeta and Piccolo may initially prove more of a challenge than expected with both having trained harder than even in the main timeline in case Freeza should ever turn on them (with the one who had ruined Vegeta's life now walking around as a hero providing enough rage for Vegeta to achieve SSJ regardless of Goku's absence), though would still likely lose to the twins due to the difference in stamina and are killed. When Freeza finally arrives, he manages to destroy the twins without difficulty and uses the Galactic Patrol's resources to find New Namek in order to revive Piccolo and the rest. With how much of a high-level area Earth has proven to be, Freeza starts surveying it more regularly as well as implementing Capsule Corporation's technology into his forces in order to assure his ships will be fast enough to help with future threats in time. It isn't long after that Piccolo and Kami concede to merge both due to the vast increase in the power scale that's emerged as well as Kami's lifespan drawing to an end. Soon after, Freeza decides it's best to help draw out both his own and the Dragon Team's strength in case even stronger unexpected enemies than #17 and #18 appear, with Piccolo informing him of the Rosat eventually (or maybe Goku would butt in to tell him of it via Kaio) and Freeza going in with Gohan due to acknowledging him as a fellow prodigy with great latent power and reasoning with Chichi Gohan would need to protect himself now that Goku was gone. Assuming Gohan had attained SSJ at that point, things progress a lot quicker. He'd achieve it anyway at some point on accident with Freeza knowing that rage is a catalyst to unleashing Gohan's latent power. Freeza may also unwittingly help Gohan master the Super Saiyan form due to training to perfectly utilise his own power without the stamina drain. Vegeta would go in with Piccolo afterwards, both training separately from each other and Vegeta having seen Gohan after the training causing him to focus on mastering the Super Saiyan form before leaving. Gohan, Vegeta and Piccolo essentially get boosted to more or less their Cell Games levels, with Freeza being far above that.

7 years later, the start of the Boo Arc goes the same due to the peaceful world but with Freeza taking #18's spot in the Budokai. When the events in Babidi's spaceship happen, Freeza takes Gohan's place and fights against Dabura. Freeza's training and potential would make him far stronger than Dabura, but the Demon King's magic would draw the fight out Dabura would use both his afterimages complimented by his unreadable Ki with a stone spit to transmute and break Freeza out of desperation. Dabura would then fall back due to his fatigue and have Babidi attempt to possess Vegeta. Without there being a large gap between he and Goku though, Vegeta either resists it completely and kills both Babidi and Dabura or lets it happen purely to catch Dabura off guard and kill him. In either case, Vegeta then fights Goku after the Dragon Balls are used to revive Freeza and Vegeta ends up winning regardless of the Majin Vegeta route due to the amount Goku would be lagging behind his canon self without the Rosat. Goku also chooses to teach the fusion dance to everyone before he leaves. As for Vegeta, though he feels some satisfaction for having bested Kakarrot, he realises he's long since moved past that rivalry as surpassing Freeza is still his true goal.

When Beerus wakes up, he immediately goes to Earth upon hearing the news that of not only Saiyans being there, but Freeza having reformed his ways and having gone there for Bulma's birthday. I'd also say that, without his empire focusing so much on internal disputes of power vacuums due to him being alive, they would've found Broly and Paragus on Vampa not long after the Boo Arc and both would have come to Earth with him and the rest of Freeza's most loyal workers. Beerus eventually asks if they know anything about Super Saiyan God after he gets his pudding, with Freeza saying he once heard legends of it but knows little. They use the Dragon Balls to learn how to bring about one and the ritual takes place. Vegeta would have likely reached the point of becoming pure hearted after spent such time on Earth and having gained a more pure motive of self-improvement in wanting to surpass Freeza rather than conquering the universe, though Paragus still wouldn't be eligible and Pan would be used instead. Broly would be chosen as the candidate due to being by far the strongest and his power would prove to be a genuine challenge for even a full power Beerus, with him barely winning due to the God form running out and through superior skill, There'd be no threat to the Earth in this scenari either and Whis soon trains Broly, Vegeta and Freeza (who would reveal himself to have already gained and mastered his Golden form through sparring with Broly).
When the U6 tournament happens, the team is Broly, Vegeta, Freeza, Piccolo and...maybe Tagoma, Shisami or Paragus? (Monaka wouldn't be used as having a motivator for training here when Broly's power was more than a match for Beerus' if he'd attained SSB by this point would be unnecessary). Freeza takes Goku's place against Botamo and Frost, though has the reactions to see through the needle trick and schools Frost on both his naiveté and despicable nature before beating him. Though having enough power to solo the whole team, he lets Vegeta fight and tutor Cabba and Broly beats Hit. Zamasu likely never gives into his evil desires when considering Freeza would stand out as an example of the good mortals can show and there'd be no timeline in which Black could securely carry out the plan anyway. Universe 7 has no trouble winning the ToP due to Freeza likely having approached Broly's level by then and Vegeta likely being stronger than his canon self due to the need to try and keep up. The Moro Arc wouldn't happen due to Cranberry having been found by Freeza back on Namek and Moro remaining in prison.