According to the lyrics, they aren’t exclusively complaining, they’re telling “good stories” about their not-so-great experience which is a different thing. Also, they never tried to be a ‘good guest’ at parties, merely that they were found to be ‘interesting at parties’ because of their ‘good stories’.
That said, I really wish they didn’t repeat lyrics so much and instead told more of those “good stories” they keep boasting about.
I don’t think he can because the RNC already happened making him the party’s nomination. The DNC hasn’t happened yet so the Democrats were able to switch candidates before they meet to nominate.
https://ballotpedia.org/ State laws and party rules on replacing a presidential nominee, 2024