The pig is placed into the roasting pit without any barrier beneath it and the coals or a shield over it to keep the earth off. It would be completely inedible if cooked this way.
Kerosene lamps are shown in regular use throughout. Kerosene has a shelf-life of at most five years and they are now long-past that since the outbreak. Making new kerosene would require fractional distillation of crude oil. They have neither the raw materials or the equipment to do this.
Negan walks among the dead without wearing walker-skin or guts. He even talks to Beta without attracting attention.