Forget everything you have heard about retro planets, its all nonsense. A retro planet is closer to earth, that means it gives more of its good indications and less of its bad. But that alone does not make it a good planet. If its forming bad yogas, in bad avasthas, its a bad planet, but it will give less bad since its retro. IF its forming good yogas, good avasthas, its a good planet and will give more good. So its a quantitative factor. And it cant be used alone, it has to be used with ucca bala and also subha and also dig bala especially. I explain this where necessary in courses such as in the PAC in astrology course.
outerplanets are not good or bad, they just have a job to do and they do it. When retro, t hey are closer to earth so they have more force to do their jobs. that's a good thing but wimps don't like it.
I have noticed that using retrograde planets, it´s easier to pick quite unusal things like winning lottery tickets or similar (that usually or mostly doesn´t fruit). Something is there, but with own swing. I think that retrograde planets can be useful if can understand how they work.
If we look natal charts, people with retrograde Mercury, quite of many them can find or look for lost things often more higher success rate that non-retrograde Mercury persons (but they tend to be much more talkative too, some of them can be almost annoying 😀).
Outer planets are not good or bad, they don't have avasthas or conditions or dignities, or uccha bala, etc etc. They just indicate the growth that is happening, so retro means closer to earth so more strength for growth. IA person will grow more with retro outer planets. and when the outer planets hit them, there will be more growth than in those with no retro outer planets.