@@SierraSierraFoxtrotThe Jerryboree is in a dimension that transcends time and space so no matter what alternate universe they are in, they can always get there.
@@SprayInk-And-CritGlitchit's a spicy soy-and-sugar based sauce used in one of China's regional cuisines. Authentically it's made with Szechuan peppercorns, which are both spicy and have a unique mouth-numbing effect (I dunno if the McDonald's sauce was made with those though).
The writers are just too damn good at their jobs. The way they seamlessly blend in story elements from multiple past episodes and create relevance with things you wouldn't think twice about is an art.
The backstory might be fake to get the virus in without questions asked but there might be some truth behind it. A Rick killing people other Ricks care for would explain why our Rick is such an asshole but willing to sacrifice himself for Morty. He loves his family but showing it might kill them