Yes. Cuba could be the "safest" place on the planet. They actually have the lowest crime rate in the western hemisphere. The tourist industry is so important to them; they make sure that tourists are very well taken care of.
Yes. They have WiFi hubs by the ETECSA. Anywhere you can buy cards that allow you to use your cellphone or laptop to log on. Likewise, they have computers you can use if you do not have your own device.
Many people in Cuba have learned English, as it is widely known as a medium for travel and they have had tourism for over 13 years now.