1. Grooming used to strictly describe a process where an adult builds a relathionships with a child or person under the age of consent with the intent of sexual abuse. Now its used to describe any relathionship where one is percieved a "vulnerable" a term so vague you can apply it retroactivelyl to any situation where the adults involved were not clones of each other. Old guy asking a young woman out - grooming. Boss flirting with his secretary - grooming. Celeb sleeping with fan - grooming.
  2. Sexual predator was always defined as someone who is in the process of planning to commit a sex CRIME like abuse, assault and rape. Today it is applied to any guy looking to score and its heavily biased against men percieved as unattractive. I even saw it used by women who were fat, but then lost a lot of weight. They described the men they were sleeping with when they were big as "predators" who "prey" on fat womens insecurities.
  3. Power imbalance problematized relathionships with FORMAL power imbalances, sperior - subordinate, mentor - student, boss - employee, today it is applied to relathionships between consenting adults with no formal relathions or whatsoever. I just read an article where a 45yo comedian met a 19yo fangirls of his, no previouis formal relation, they texted back and forth for a while, then he suggested a "back at my place", and reddit is now calling it "grooming" because apparently he held to much "power" over her since she was "starstruck".