Re:Fire suppression system, yay or nay
You need to make a list of questions and ask YOUR health dept, fire, building, city, county, etc. They will have the CORRECT answers, not opinion from random people spread across the country. We don't know the correct answers.
What's going to happen when you buy a trailer with only two sinks, no fire suppression and a grey water tank that is too small because I told you it Should be ok and it's not?
Go to the source for your answers on critical items, read the food and building code requirements several times, know them better that the health dept, then come here for other advice or ideas.