your graphics card is certainly part of the issue but you can't do anything about that. If you are using your internal hard drive that is part of the issue and you will want to connect a firewire external drive. If your computer can't access firewire I'd just sell it and get a different laptop that can (via thunderbolt or whatever). Assuming you can connect firewire then do get a fast 7200 rpm external drive for your FCPX work and upgrade to a minimum of 8gigs...more if you can.
It's also possible your export is having problems unrelated to the basic speed issue...but 4GB is pretty small and it should definitely be used in conjuction with an external drive.
Your GPU isn't your MBP's strong suit, but what are the details of your project? What the length and format? What format were your clips? Many graphics and/or still images? Extensive effects? How did you export?
FCPX seems to benefit from as much RAM as you can throw at it (which I think is 8 GB for your machine) but I doubt that it has anything to do with your export experience.
Follow Digibudll's advice; get a fast external Firewire drive and put your projects and events on it at the root level of that drive. And make sure you have at least 20% free space on your boot drive.