I plan on having an ocean-planet with a breathable atmosphere built into my current setting, orbiting its host-star (a K4v main-sequence star) a short distance beyond its frost-line, with oceans that are much deeper than those of earth, making up most of the planet's mass.
It doesn't have any natural satellites, is about 1.4 times as massive as earth (8.361*10^24 Kg) has a radius of 1.3 Earth-radii (8,282.3 km) a rotational period of 4.4 days, inclination of 5°, and a surface-gravity of 8.129m/s².
i'm not sure if those mass-radii ratios are entirely realistic because planet-radii seem behave weirdly when it comes to ocean-planets, but those were the proportions i ultimately went with.
My plan was for the planet to have surface-temperatures that constantly remain below 0°c, with minimum temperatures reaching up to -130°c.
Now i know that our own solar system has a purported ocean-moon, i.e. Europa, but unlike the planet i planned on implementing in this setting, it neither has a liquid surface, nor a breathable atmosphere.
I intentionally describe it as "liquid", because it doesn't necessarily have to have oceans made of water, it would be enough for them to be of a liquid which doesn't produce deadly vapors that could kill humans.
My question would be: Is it possible for a planet like this to exist, and under what circumstances could this planet retain liquid oceans under temperatures below 0°c while still having a breathable atmosphere?
Additionally, what could it look like given the question's parameters? (i.e. things like color of the oceans and atmosphere given the chemicals they're made of, or possibly the weather it might produce.)
*edit: You might realize that some of the responses look like as if they're referencing the question incorrectly. I edited the question heavily to make some more clarifications, hence the bounty as well.