Firstly, it’s worth pointing out that the Brass Coast are Honest this isn’t nessecary stopping you being sleazy but it’s worth bearing in mind.
Also on that note this thread On the profitability of healing talks about charging for healing
Potions:
On props there will be potion physreps for sale at the site, making drinkable potions that fit the descriptions wouldn’t be too far, but it is definately more than is needed
Sleeping rough:
I have no idea if this would be allowed, but I wouldn’t recomend doing it, firstly the IC field is quite busy and even if you sleep out of the way, I can imagine someone taking a shortcut through some tents and stepping on you. Secondly weather at events can be somewhat variable there have been events where it has poured it down with rain for most of the event and most of the field turns into a swamp.(Now hopefully the events moving later in the year will prevent a repeat of the worst of it, but Murphies law suggests the time someone turns up hoping to sleep rough we will have all the rain.)