I think that one of the most important thing a recruiter can do is stick to their commitments. How many times have you been told by one that they will contact you/get back to you/do xyz and then found that they have not and that when you follow up they are elusive and hard to track down. I genuinely think this is poor organisation rather than malice but it still does not feel nice being at the other end of it
I definitely have to agree with this. I cannot stand when I am told that I will receive a call back on a certain day and then I call back to follow up to find that they filled the position. If the recruiter/interviewer is not going to call me back then please do not tell me you will contact me on a certain date. This only waists my time.