Huh. We seem to be having a very different experience so far. Our realtor, knowing that we are first-time buyers has been extra careful to explain what we need, when we will need it, and to let us know about all the components before they come up. You might want to have a discussion with your realtor and explain your frustration to him or her and ask that they change their behavior to be more careful of what you don't know yet.

Mind you, this is all talking out my hat since we aren't as far down the road as you yet, It just seems like the things you mentioned in this post are all things that we've already discussed with our realtor which says to me that perhaps your realtor isn't being as informative as they should given that you don't know what to expect. I guess this all boils down to a comparison of relative experience hopefully offering you some perspective?