Hey I can answer at least some of your post. If you bought on Coinbase, it'll be better if you use their other website GDAX like you're looking into, because you can make limit trades which have NO FEEs to utilize. To transfer your coins from Coinbase go to GDAX, log in, then click deposit on the left hand side and then you will see 'Coinbase Account'. From Coinbase account the transfer from Coinbase to GDAX and vise versa is 100% FREE so that's great. Transfer your BTC and then you can hover over the Top Left of the website where it says BTC/USD and you can exchange BTC/LTC, BTC/ETH, and of course BTC for fiat. GDAX is a way better alternative from Coinbase in my opinion because of the free limit trades.