Water line under freezer door flows very slow. Same happens when I connect it and use the water dispenser obviously. Checked the cold water storage coil of hose behind crisper trays and water seems to be flowing fine, just slow w/ the occasional bubble. Plenty of water pressure going to the water inlet valve in back. Could it be a bad valve?

If the refrigerator has a factory-installed water filtration system, I would first bypass (or otherwise eliminate) the water filter. If that doesn't solve it, check for a kink in the plastic tubing somewhere in the refrig. Probably not likely if the unit is older, but you didn't say how old the unit is. A water valve isn't usually the cause of a water restriction, but I have seen it a couple of times. Most of the time I run across this problem, I find its due to a self-piercing saddle valve connecting the waterline to the house plumbing. If you do have one of these installed, get rid of it, even if its older. If it isn't causing you a problem now, it will sooner or later anyway. At least if it doesn't solve this problem, it will prevent one in the future, and it could then be ruled out.