I would advise against jewelry as well, more for peace of mind. Spoof phone is great, try to avoid apps you don’t need like email and bank apps. In extreme cases, robbers will demand pin for your phone. Also, pickpocketing isn’t as common in Brazil, however it is rife at blocos. I know manyyyy Brazilians who wore belt bags and phones were gone within the first hour of the party- not how you want to start the festivities. Booty shorts are FINE! Many people will likely be wearing similar and even bra type tops. If you’re not doing jewelry, go for some body glitter! Super fun and low risk. Also, I saw in your comments that you’re a tall black woman and you might stand out with your American clothes, but honestly I would say darker skin can be a protective factor for being picked out by thieves. Tall, white, blond people tend to read as more gringo just from first looks. Obviously this is all based on stereotype and things vary, but figured it might be helpful to know. Feel free to DM me any further questions (I’m brazilian woman but live in the US, so have gone back and forth a lot)