The synonym of glib would be insincere...
if you look up the definition in the dictionary it tells you that glib refers to someone that is insincere
hope this helps :)
1.in the book they get chosen a career at age 12 instead in the movie it’s at age 18
2. This first memory in the book is being stung by a bee in the movie it’s a sunburn
3.in the book Fiona is not mentioned a lot but in the movie she is seen and mention more.