Right now it is latest time to sale your BTC and receive USD at very good price, - http://preev.com/, later you can receive much less. If you look in BTC charts for 1 month, 3 months and 1 year - https://coinmarketcap.com/currencies/bitcoin/, you can understand, that BTC price reached max.
I don't think so. I think it will peak around at least $30k, probably by end of March. It is definitely too early to sell, but I think Ethereum will outperform bitcoin for sure.