Sue and Will's date was to be on Wednesday, and cheerleading Nationals is on Saturday. Kurt says that after the failed date, Sue was absent for a few days, but this timeline would only give her two days at most to be absent.
Brittany and Santana pass by Will on their way out of his apartment and Brittany whispers "I'm sorry Mr. Shue" but her mouth doesn't move.
In "Funk" it is expressed by several characters that Rachel is a vegan (does not eat meat or other animal products). However, in the episode "The Rhodes Not Taken," Rachel is seen eating pepperoni pizza with Finn on their bowling date.