Rad, before I get started I have a question about Venu's placement.
In my own observations when a planet is within a degree or so from an angle I have tended to interpret it as if it was in the next house from the perspective of just beginning, taking the first steps, into a new cycle since it really seems to take on those characteristics of the angular house more strongly than the cadent house it is in.
I also have the intuition to question the birth time here. Perhaps Venus is more in the third than we thought? How would you suggest I proceed with working with Venus in an accurate way here?
With a planet this close the the proceeding cusp the actual house the planet is in serves as the baseline upon which the following cusp, house, is then added too. So in Darwin's case, the 3rd house is the baseline upon which the 4th can be added. The very nature of his life demonstrates the accuracy of his 3rd house Venus: not only in the life of Darwin, but the life that came before that as well.
God Bless, Rad