NEVER! I would rather get sick - and that has not happened yet
Depends on if I’m making it just for me or for a crowd.
For a crowd, I add worchestershire sauce, garlic POWDER (never salt) and black pepper.
For me, I’ll also add cayanne pepper, basil and oregano.
Mix well before grilling.
On top, always add both raw and grilled onions. They have different flavors that compliment each other nicely. (I discovered this when I ordered a hot dog and forgot to tell them I wanted the onions grilled. The obliged by throwing some on for me and it was fantatic)