Narine probably won't make the WC. He's been reported twice for illegal bowling in the CLT20 so he's probably going to sit out soon. He'll be a marked man if he gets to the WC.
Why do you believe Windies have a better chance than England when England have won both of their last two ODI series against WI, both home and away? In addition, WI lost heavily to Aus (5-0) last time they were there, were beaten at home by Pak, and also lost an ODI series to Bang recently. They've had dreadful ODI form.
That said, I don't think Windies are no-hopers either. ODI form is so flaky among the teams that anybody can win on any given day. Eng beat WI in the Caribbean in Feb/Mar this year, then lost heavily to India in England, now India are losing to WI in India. So all three teams lost in conditions expected to suit them, and won in conditions where many thought they would struggle. ODIs, go figure.