Habitable Venus

[The Astronomer]

IIRC, the current thought is that a major cause of the Venus hothouse is that it rotates extremely slowly. This leads to just about no magnetic field, and in turn that leads to the lighter components of the atmosphere being stripped away by the solar wind. This apparently happened because solar UV split water in the upper atmosphere and the hydrogen was blown away. Which in turn leads to very low water levels. Early life lived in the sea, a bit difficult if there isn't much sea.

So would a Venus rotating at something close to the rate Earth does remain habitable to date? Has any simulation work been done?

Incidentally, no water leads to no plate tectonics.

It's debatable. A friend of mine had seen like five competing theories on why Venus lacks a magnetosphere:
1) The Venus core is completely solid
2) The Venus core is completely liquid
3) A collision changed Earth's core's composition, allowing it to persist longer than Venus'
4) Venus spins too slow (yours)

They couldn't remember the fifth, so I'll add what I've seen to complete it:
5) Venus' lack of plate tectonics lead to low temperature gradient, resulting in no convection in the Venus mantle

I believe some studies show that magnetic fields are not a major factor anyway. What prevents water from escaping to the upper atmosphere in the first place and be split by radiation is a cold trap.

On slow rotation, some say a Venus rotating close to Earth's rate would not be habitable due to the lack of cloud formation on the dayside to reflect sunlight, which is twice as strong. A slow-rotating Venus would still have the cloud formation which is helpful.