7th lord and retrograde conspet

good evening sir
sir I have a question about the concept of retroged plant. that if someone have any retrograde plant in libra then it will be also work like 7th house . because as you said Libra also should be consider as 7 th house …
and one more thing
If someone have ast 7th lord which is setting with ketu in very close conjunction like gap between both of them only 1′ degree …then what will be the effect…..