first, do you have the squid instaled and configured? or any proxy that you use?
In the iptables you are masquarading your laptop2 to the router, so all the packages that your laptop2 send to the internet or the router is going as yout server ip.
All the packets that your laptop2 forward to any location is forwarded, so your VPN will work. but in order to have internet you need a proxy instaled in your server linux, i personally prefer squid
Please, put more information about it