Am I OK with Euros during my stay in Cape verde or must I have local currency to start my sta? I am on a charter (all inclusive), so I would not expect to need much, but I am curious about the use of the Euro in general on the island.
On Sal, Euros are accepted pretty much everywhere. On one of the other islands, there may be difficulties using them. CVE's (Escudos) are on a fixed 1 Euro = ~110 CVEs. If you exchange at the bank or airport, this is the rate you'll get. If you use Euros in local stores, you'll get a 1 to 100 rate (losing about 10%). Any change will be given in CVEs.
CVEs are only used in Cape Verde and nowhere else, so any you've received that you don't wish to keep (as souvenirs), you should definitely change back to Euros before you board your flight.