Can a runner trying to score hurdle a catcher?

Answer 1

Yes but it's fairly unlikely considering that faster players are usually middle infielders and outfielders that spend a lot of time working on their speed. Also, catchers have a lot of wear and tear on their knees due to having to crouch all of the time.

Answer 2

Depending on your league rules. In general, the answer is yes, provided that your league has not adopted a "must slide rule".