Earlier quoted context omitted.
Would you normally expect a psd to contain exactly specified type sizes? I don't use psd comps myself, but I'd treat them as more sketches and guidelines as to actual style and placement, rather than some sort of specification document, because it's a different medium and text handling in ps is pretty basic - it's really not suited to extensive text layout.
To pile onto wonderyak's point, I am a developer, not a designer. I wish I was also a designer, but due to where my talents and experience lies, I cannot do both well at this point. The problem is that I cannot tell what is and what is not important in a design that is handed to me. I have had conversations with designers where I inadvertently change a margin on a callout box by +/- 10% and the designer notices and e…
I would never accept a photoshop comp as a developer or send one as a designer and expect it to be reproduced exactly, because it's in the wrong medium, and it's a terrible way to specify things like text sizes or column widths except as a general indication. There has to be some give and take (and a lot of feedback) in a process going from something static and done without grids like a sketch (e.g. a psd or pencil sketch) to a final website, so what you describe in your feedback from the designer is a normal process I think and to be welcomed, it's inevitable in the translation to HTML. The design will change as it has content added and goes into templates, adaptations will have to be made, and the design must be flexible enough to deal with that, and your designer should be around to help with it - if they're not they're not doing their job properly.
I guess what I'm trying to say is that dealing with change is part of the job in design, and your designer should gracefully do so, in which case it is no problem if they gave you a vague psd - it should be vague at the early stage before implementation, because there will be changes, and additionally, html is just not a medium which allows us to specify layouts which are exactly the same in all conditions - browsers, text sizes, fonts, scripts, proxy servers mangling images, user stylesheets all affect layouts, so you have to accept that not all users will see content at exactly the same sizes or with the same fonts or even the images as you intended them (if they're on a mobile network, a proxy might have downsampled the images).