Is Super Saiyan rose the strongest?

Super Saiyan Rosé is more powerful than Super Saiyan Blue because not really for its general base strength but more so its adaptability. From what we've gathered, Rosé should be 1.2x stronger than Blue.

What is the highest Kaioken Goku goes?

X20 Super Saiyan Blue Kaio-ken X20 Super Saiyan Blue Kaio-ken - The highest obtained level Goku can use for Kaio-ken Blue.

What kind of Saiyan is Super Saiyan rose?

Super Saiyan Rosé (超スーパーサイヤ人じんロゼ, Sūpā Saiya-jin Roze) is a Saiyan transformation which matches Super Saiyan Blue in strength. In the anime, this form is simply Goku Black's version of the standard Super Saiyan form while in the manga, this form is a Super Saiyan God Super Saiyan form, being the divine counterpart of Super Saiyan Blue.

Which is better Super Saiyan or Kaio ken?

Super Saiyan level 1 is far superior to the Kaio-Ken even at the times 20 level. In Dragon Ball Z: The Return of Cooler, Goku again uses the Kaio-ken on Meta Cooler, but it again proves far too feeble, forcing Goku to go Super Saiyan soon after.

Why does Goku Black use the Super Saiyan rose form?

Goku Black is shown using the form as much as he wants with no drawbacks, possibly because he already mastered Goku's power and also because he was born a divine being, and all he needs to do is keep increasing his power in this form.