What is the ruling on saying "You did well," "Excellent," "Wonderful" with the intention of attributing credit to oneself? Does this fall under attributing credit to other than Allah Almighty? And what should I do about wounds on the parts of the body used for ablution, which form blood that is difficult to remove, and more blood comes out when attempting to do so?

The best cure for waswas (whispers/obsessive thoughts) is to ignore them and not pay them any mind. A person praising someone does not attribute favor to other than Allah, and the Prophet, peace and blessings be upon him, praised his Companions. Wounds and the scabs that form on them are part of the body and do not need to be removed. If there is blood on them, wash it if possible without harm. As for washing the wound itself and the blood in it before it dries, it is obligatory to wash the entire limb, including the site of the wound, unless there is harm in doing so. The appearance of blood after washing the limb does not affect or invalidate wudu (ablution).