My lo is similar in that he is reluctant to let me feed him from a spoon. I tend to try spreading or squashing his food onto a rice cake and each time he takes it out of his mouth quickley squish a bit more on! I know what you are saying about the mess when they use a spoon. I let him have it, but hang onto it firmly and try to guide it into his mouth. Tofu is a good finger food, for protien and calories. Also mixing rapeseed/flaxseed oil with food/pasta/ whatever increases the calories and provides the essential omega oils.
Hope this helps a bit!