Hello, I was a tour director in Rio for 6 years and was able to keep everyone happy and safe by sharing these few tips....
1. Stay in a hotel in Ipanema. It is less populated and more upscale than Copacabana, but has all the great restaurants and shops.
2. When going to the beach, do not bring anything but a towel and flip flops. Leave anything of value or importance in the hotel safe. Most hotels in Rio have safes now in your room --- usually located in the closet.
3. Don't use the standard public buses in Rio -- the ones where you get in the back of the bus and pay in the back of the bus and then go to a turnstile -- to sit in the front. Tourists notoriously get pick pocketed on these buses, and since they go to all parts of Rio --- including the suburbs ---- may be difficult to navigate. There is one type of bus in Rio that is safe -- and that is the "Frescao", called that because they are air-conditioned.
But, to be honest -- to avoid any problems and get to where you want to go quickly --- use taxi cabs. Make sure the driver uses the meter. Try to have the address you are going to written down on a piece of paper, in case the driver does not understand your English or your accent. It happens. Depending on the economic situation in Rio when you go, there may be a chart on the window of the cab -- where you will convert the price on the meter -- to the current legal price that you will be expected to pay.
4. Don't walk around Rio with expensive watches or jewelry. Try to blend in with the Brazilians. They dress casually and stylishly.
5. Stay out of Favelas. These are the shanty towns that dot the hillsides in Rio.
6. Don't walk alone on dark streets or the beach at night.
7. Don't carry around large amounts of cash. If you plan on buying something expensive -- use a credit card, or have the shop deliver it to your hotel -- and pay them at the hotel. This is a common practice.
8. You may arrange a private guide for your first day. This is a very good idea to get insider tips from a local when you arrive.
If you need help arranging a private guide, please feel free to contact me at -snip-
And lastly, remember the above items, but do not forget to enjoy yourself! Rio is beautiful and the people are very friendly!