Goku had a senzu bean on Namek

[SSJ2]

As per CC's request in the challenge thread, here is a topic.

In this what if, Goku kept a bean instead of giving one to Vegeta. When he eventually fights Freeza and hits him with the Genki-Dama, instead of going Super Saiyan, he eats the bean, and gains the ability to use Kaioken x20 freely (he didn't gain power from a zenkai).
Could he fight the worn out Freeza and win? Assume that he won't let Freeza get to 100%, so his weakened 70% would be the most power he could output. Who would win?

 

[Void]

Even a worn down Freeza at 70% should be able to fend off a 20x Kaio-ken Goku unless he takes a direct Kamehameha hit. Goku's only hope would be conjuring up another Genki Dama.

 

[Captain Cadaver]

Not sure why he wouldn't have used it immediately after the Ginyu battle when the healing chamber was too much of a risk by comparison in terms of time, but I'll go along with it.

I don't see there as being a reason for Freeza's power to have decreased, as it'd contradict the notion of Freeza going to his 100% and could even calculate what percentage he was at whilst powering up. That said, 70% Freeza would still stomp, though it would mean Freeza would use up slightly more stamina than in the main timeline. Considering that, their battle after Goku inevitably goes SSJ once Freeza starts taking shots at the bystanders would be slightly shorter due to some additional strain on Freeza's part. In order for this to lead to any changes after this battle, I'm going to say that the slightly increased loss of power would lead to Freeza not surviving Goku's blast.

With that said, it changes things with the Cell Arc due to Cell not having Freeza's cells. I assume Cold would still come to Earth, but without the primary source of Cell's evil in Freeza, I'd say there'd be an increased likelihood of Cell being redeemed. This leads down two possible roads.

A. He doesn't have a change of heart. Timeline remains the same after his death.
B. After returning as Super Perfect Cell, his somewhat more honourable nature leads him to not killing Trunks and having a fair fight with Gohan. Despite Gohan's superior power, I'd see Cell's advantage in skill and techniques giving him the edge and winning against Gohan. By that point though, I could see Cell as being too fatigued to take on Trunks, Vegeta and Piccolo, or after having proved his position as the strongest, would do what Beerus did and spare everyone in the hopes of seeing how strong they could become. Cell would leave the Planet and the arc ends as in canon. Goku would still remain dead, since he'd see Gohan's actions converting Cell as proof Gohan had succeeded him in defending the Earth.
After this, I'd go with the route from my "What If Bulma Married Goku?" scenario of Cell allowing Babidi to control him in order to pull a Majin Vegeta (which still happens as well). This leads to Boo being revived far earlier, Cell getting his ass handed to him before retreating and training in the Rosat for a rematch. Cell would form another Cell Games to face Boo, with the ~10 day waiting time leading to Boo and Satan becoming friends, but the gunmen not appearing.
When this happens, Cell wrecks Boo, but Satan gets caught in the blast and is fatally injured until Boo heals him, with the rage leading to the split and Boo becoming Evil Boo. Cell is then defeated, either being killed or absorbed. It doesn't matter too much, as when it comes to the Gotenks fight it would end up the same as before. After this, things go the same way as in the Boo Arc, except with Shello being revived.

For Super, this would lead to a lot of changes. Cell would be chosen instead of Boo, with him racking up enough victories to make U6's victory easier. Through intense training, Cell would probably reach SSB tier by the time of the ToP like every relevant character and replace Freeza. With a far greater moveset, it would make U7's somewhat easier.

 

[withheldforprivacy]

If Vegeta remains injured, Recoome and Butta remain alive. When Ginyu and Jeice arrive, Goku has to face
both of them at the same time, so he shows them his true power (kaioken) right away instead of risking
fighting them both. Ginyu takes Goku's body and leaves along with Jeice. Goku says to Vegeta he will return
later to help him and tries to fly and follow Ginyu.
Gohan and Krillin now have to face both Ginyu and Jeice at the same time. Meanwhile, when Recoome and
Butta regain consciousness (neither of the two had anything serious), they kill Vegeta. Ginyu and Jeice kill
Krillin, Gohan and Goku (even if Goku takes the senzu, his PL is 30k or so, so he's no match for Jeice), so
Freeza's empire continues, unless Gohan can get an absurd enraged boost during that fight.
If Gohan gets an enraged boost, he kills Jeice and Ginyu, before the latter can try switching again (i don't
think that, in his enraged state, Gohan has the reason to think 'let's not kill Ginyu, for dad wants his body
back'). Butta and Recoome arrive soon after. Finding out Gohan killed Jeice and Ginyu, they lose their will
to fight. Gohan's rage has somewhat subsided by now, so he's convinced by Goku not to kill them. The two
soldiers are forced to join forces with the good guys.
When the wishes are made to the dragonballs, the third wish is used to transport Piccolo right next to them.
Freeza shows up. Gohan kills him before he can transform. Goku gets his body back with dragonballs.
Recoome and Butta either choose to become wandering mercenaries or follow Z fighters to Earth. If they do
so, they can get at least the same plot gains as humans by training.
Considering Goku's body 'died' when Gohan killed Ginyu, the heart virus died as well (i theorize Goku got it
when he was at hospital after his fight against Vegeta) and the virus is not resurrected, so Goku never
gets sick. However, that doesn't make a difference, the Androids still dominate. Gohan transforms into a
Super Saiyan at some point. Since Bulma has no offsprings (unless she coupled with Recoome, lol), she rides
the time machine herself.
Alternate Bulma warns them about Androids and informs them about SSJ transformation. Over the following
3 years, Goku unlocks the form, but not Gohan. Piccolo is at most in the low millions, because he never
fused with Nail, so his potential did not become insanely high.
SSJ Goku defeats Nineteen and Dr Gero is chased to his lab, where 17/18/16 are activated. Since their
target is to kill Goku and he does not know Instant Transmission to escape, he gets killed. Gohan becomes
SSJ because of rage and attacks the Androids, but he's defeated. The mechanical trio spares Gohan and the
rest of the group and go away to find something else to do with their lives.
Piccolo goes to fuse with Kami. Kami accepts; after seeing Androids kill Goku, he considers them a threat.
Cell shows up at Ginger. Since that version of Kamiccolo is weaker than in canon, he gets absorbed by Cell.
The bio android leaves Ginger Town without anyone else finding out about him yet. Meanwhile, Gohan and
Krillin have gone to Gero's lab, collected the blueprints and given them to Bulma (in canon, it is implied they
intended to search the lab even before finding out about Cell). After that, it is hard to decide whether
Cell absorbs Androids or whether they are deactivated first.

1. Cell finds and absorbs the Androids
Maybe that version of Cell is weaker than canon, because he has no Freeza in him, but he's still strong enough
to stomp everyone. Earth is destroyed. When Beerus awakens, Cell produces 5 Cell Jrs and performs the SSJ
God ritual. He becomes Beeruses student. Freeza is not revived, since King Cold is still alive, so there is no
anarchy in the empire. Cell takes part in Universe 6 tournament. Zamasu takes Cell's body and Zero Mortals
plan succeeds.

2. Z Fighters deactivate Androids before Cell can find them
Cell is either killed by the combined forces of Z fighters or absorbs Gohan and wins (which results in same case
as Case 1, even though Cell will now be weaker). If Z fighters win, Dabura defeats them all 7 years later.