Yes, definitely.Fight like cats and dogs:
1. Even it is only two people are involved, it is still cats and dogs.
All of the above.2. Frequently? Violently? And Long-lasting?
The phrase "They fight like cats and dogs" suggests a violent encounter. True, that might not always occur between two people who fight like cats and dogs.3. Fighting is actually arguing, not people pulling each other's hair.
Yes.4. Can politicans and two rival football teams fight like cats and dogs respectively?
Yes.Love at first sight:
1. Can it be one-sided?
Either one.2. Always face-to-face? Ok from a distance?
Yes.3. Seeing a person in the movie the first time and falling in love with that person, can you say it was love at first sight?