The lines were supposed to convey hands as yes, either useless or harmful. Sort of in the "everything I touch turns to sh*t" attitude, where the second stanza has hands hurting someone else, the third is hands being useless, and the fourth is hands as destruction. The opening stanza is supposed to reflect how people expect to rely on my hands or my physical support, which are just a "moldy house" and are therefore unreliable even though they look sturdy from the outside. Hands are the embodiment of our physical effort, and my words always seem more able to comfort and soothe than my physical gestures can give. 

Good! Am i correct in assuming that the the third and last stanzas, the former calling the hands useless and the later, something that burns, implying that the speaker is either ineffectual in what they try to accomplish, or else actually harmful to someone else? I got the impression, when I read the line saying that it is the tounge that sooths where the hands burn, that the speaker feels his/herself to be all talk, or else someone who gives promises they have a hard time keeping. Or someone who talks sweetly, but isnt good in reality... so which is it?