1. I believe he is saying "Now is your chance. Call it off" to mean Trump should say he does not want to be president.
2. I believe they are referring to the previous statement. Meaning Aunt Belinda smells like fullaffle and wants to shave his mustache. Or that Aunt Belinda at least wants to shave his mustache.
3. "The goldfish of pre-teens never had a chance time" could have some deeper meaning, but to me it just seems to be nonsensical which is why it is "funny".
4. He was watching a cage fight (like UFC, mixed martial arts, etc.) and puked while watching it.
5. This and the previous sentences talking about bars are mocking Trump and the way that he speaks (i.e. a big wall, a beautiful wall with a big door, a magnificent door; etc.)
Hope this helps and let me know if you ever need help.