I only put a couple skill points into melee specialization throughout the whole game. If you are getting hit a lot you could put a few points into shield blocking (it doesn't look like it would be that effective with just 1 or 2 skill points), or simply rely on stat boosts or more potions. If you have the gold, Sharpen can be learned, used and then unlearned (in which case it would be better to wait until you have a weapon you think you may be keeping for awhile), if you are not going to be using it frequently.