multiple address? I've never heard of it. but i use myetherwallet for my altcoin asset wallet. and I use the official wallet in my country for bitcoin and others, and for exchange from crypto to local currency. I am sure you must also do the same thing in your respective countries to exchange crypto assets into local currencies.
There is no official wallet for bitcoin even bitcoincore is not an official wallet so don't consider yourself as official wallet guy. Using local exchange or peer to peer sites like localbitcoin also can be useful for conversion into your local currency but it is not meant for storing.