Muggles' Guide to Harry Potter/Characters/Andrew Kirke

Overview
Andrew Kirke is a Beater on the Gryffindor Quidditch team. Along with Jack Sloper, he takes over for Fred and George Weasley.

Order of the Phoenix
In the last meeting of Dumbledore's Army before Christmas, Angelina Johnson tells Harry that they have finally managed to get replacement Beaters. Alicia Spinnet says the new beaters are Andrew Kirke and Jack Sloper, and that they are nowhere as good as Fred and George, but were the best of a very bad lot.

On February 14th, Ron says that he can't go to Hogsmeade because Angelina wants a full day's practice. Ron is sceptical that it will help, because Sloper and Kirke are even worse than he is.

The following weekend, in the match against Ravenclaw, it is mentioned that one of the low points of the game is Kirke shrieking and falling backwards off his broom as Zacharias Smith zooms towards him with the Quaffle.

Half-Blood Prince
When try-outs happen, Kirke is passed over; the new Beaters are Jimmy Peakes and Ritchie Coote. It is not mentioned whether Kirke tries out for his position or not.

Strengths
Andrew appears to have at least some knowledge of Quidditch. He is shown to not be a particularly good Beater, but he does successfully try out for the position. As a result, he is eventually part of a team that wins the Quidditch Cup.

Weaknesses
Despite liking Quidditch, Andrew is not very good at it.

Relationships with Other Characters
Andrew is presumably on relatively good terms with Jack Sloper, as they work together as Beaters on the Quidditch team. By association, he will also know everyone else on the Quidditch team.

Questions

 * 1) Why is Andrew on the Quidditch team when he is not very good at Quidditch?
 * 2) How old do you think Andrew might be? Why is this?