Well... "Does it need an EGR delete?" is kind of my point about more info. Just deleting the EGR won't necessarily fix you problem unless the EGR valve needs cleaning or you have a blown EGR cooler and if the EGR valve is the problem cleaning it or replacing it is a LOT less money and hastle than a delete. If it's a blown EGR cooler then there is a reason it blew. If you don't fix the cause you'll have more/bigger issues down the road.
It could be an EGR problem, but it could also be a glow plug problem (like the code says), an FICM problem, fuel problem, computer problem, turbo problem, and on and on. If you can check some temperatures, boost readings, pressures and voltages you'd be much more likely to find the root problem and be able to fix it rather than just try to replace parts and get lucky. That's why I was asking about the monitor and suggesting you start with some things you can check on easy enough on your own without spending money for nothing.
As for the #8 glow plug code. IIRC it's most likely the glow plug control module not the plug itself, since you changed it and the code is still there. You can swap the module out with one you know works or you can check the red wire on the black connector, it's the #8 circuit. Compare the resistance on a few of the circuits, if #8 is close to the others you know it's a bad module.
Sorry about the long wait for a reply, I don't always have much time for an answer! Also the Ex forum isn't heavily traveled, you might try the General Discussion forum for quicker results, most of the Ex owners only seem to come in here once a week or so.