Were there similarities between Pernell Whitaker and Floyd Mayweather Jr?

Yes there are some. Both were elite defensive fighters. They did it in different ways. Mayweather was a conventional fighter who fought behind his shoulder. Rolling and countering in textbook fashion.
Pernell Whitaker used upperbody movement from a southpaw stance. His agility played a big part in his elusivness. He would get very low almost to the canvas at times.

Both had elite level reflexes and quickness. Also not big hitters Both had underrated strength.

 

Yes. Both men very hard to hit, with Whitaker getting the edge on killer instinct.

 

Similarities:
Master of defense
Counterpunching expertise
Excellent footwork
Great at fighting on the outside and inside

Difference:
Southpaw and Orthodox
Whitaker had a better jab and work rate
Mayweather was more reliant on accuracy and perhaps has the edge in punching power
Whitaker’s defense was based on his upper body movement and reflex while Mayweather’s defense was more on his shoulder roll and tight guard although both also relied on elusive footwork.

 

Mayweather idolised Whittaker, and was inspired from his style.

 

Really, really debatable. Pre-welterweight Floyd finishes/KOs were NASTY