Just a few observations that might help. Firstly apart from Sun and Moon all planets turn retrograde at some time. However the amount of time that they are retrograde is not proportionally the same.
Approximately:
7.7% of the population has Venus retrograde in their natal chart. This is the lowest proportion for any planet. The remaining planets and percentages are;
Mars 9.6 %
Mercury 18%
Jupiter 33%
Saturn 37.5%
Uranus 42%
Neptune 43%
Pluto 44%.
There's a very good chance then, that anyone person has at least one of the outers retrograde. Indeed the average natal chart has 3 retrograde planets, so it's the charts with 1 or zero retrogrades or 5 or more retrogrades that are 'unusual
I've no statistics on the number of persons who have lost a father in someway (died, abandoned, forcibly removed,etc) but it would be interesting to test BigLuna's obeservation about lack of father and Saturn Retrograde. I'm not challenging the link, I'm simply taking up BigLuna's point about it being a real world relationship and therefore it's testable.
Traditional Astrology sees a retrograde planet as being accidentaly debilitated. That does not make it malefic, unless it was a malefic to start with. So Jupiter doesn't change from being benefic to malefic each time it turns retrograde. The accidental debility makes it more difficult to express itself and it's energies. Rather like walking backwards makes it difficult to get where you're going (but not impossible).
My personal view is that that is the best way to view retrograde planets in a natal chart, they need extra effort to ensure that their energy is positively used. They should not be seen as insuperable barriers, or the inability to use that planetary energy constructively.
Traditional Astrology did not deal with the outer planets as they were unknown, so whether being retrograde for them has the same effect, (as they're retrograde almost as often as they are direct) is debatable.
The latter point also stresses the role of the outers as generational planets, if (and it is an 'if') retrogradation makes little or no difference to their effects.
We seem to have regular threads about Mercury Retrograde but Venus and Mars, where retrogradation is more unusual don't seem to feature that much so thanks to Maggie for starting a thread on Venus Retrograde.
For those wishing to pursue the effects of Retrogradation, Erin Sullivan's 'Retrograde Planets' is a good read.