Making imitation Bahn Mi in huge batches. Need to know what elements are crucial and which ones are just "nice to have"

I'm making dinner for my church's group meeting which will be amateur Bahn Mi. I don't think it's that hard, but given our limited budget and time, I need to make choices about what I should and shouldn't spend extra time on.

Here's a list of typically important things in a good Bahn Mi. My question is, which or these ingredients are absolutely crucial to getting a convincing Bahn Mi taste, and which are just for that upper echelon of flavour.

• Pork or chicken marinated in some sort of BBQ or sweet marinade (this is easy)
• liver pate (want to avoid this if possible, here in Australia many bakeries don't use it anyway)
• Pickled carrot vs unpickled carrot?
• Regular mayo vs siracha mayo

Just to be clear, we just want this to be good and satisfying, not amazing and certainly not authentic.