So several days have passed and I have adjusted my editing routine with the feedback from this post in mind. That is to say, that I won't bother with posts until OP's 5 minute grace-period expires. I dedicated about an hour to this process last night, and here are some findings:
1. The sort of questions that I am interested in editing (potentially good questions, but poorly presented) seem to be largely ignored through the grace-period.
I was concerned that these types of questions may be targeted by downvotes and close flags, but I have not found that to be the case in practice. This seems to have worked in favor of the questions I have edited, because many of them have gotten favorable responses following the edit.
2. The sort of questions that I am not interested in editing usually do not survive the grace-period unscathed.
By the time I get to them, there will usually be a comment or two questioning the quality of the post. This is helpful to me as an editor, because comments from other users help me to determine if the issue is something that can be fixed through editing, if the question should be flagged for closure, or if it is something that I should move on from because it is outside of my ability to determine.
3. The quality of these edits have improved, because I am not pressed for time.
Since the questions that I want to edit are largely being ignored, I can take as much time as I need to fix major issues in the presentation of the question. If there is something that is a problem but I am uncomfortable changing, I now leave a note in the Edit Summary for other reviewers to see.
4. Last, but not least: that rude "Community" guy does not reject my edits anymore!
(Who does he think he is, anyway!?) This may seem trivial, but every suggested edit I've made with these changes has been approved without complaint -- by man, or machine.
This change has been very beneficial to my editing, and hopefully to the Stack Overflow community as well. I came to meta really troubled by the problems that the grace-period causes, but I see wisdom in having something like that now. Besides giving OP some breathing room to fix their own mistakes, allowing some time to pass before editors comes in allows the community to assess whether the question is worthwhile in the first place.
That said, the answer to the question I have posed is still somewhat ambiguous. Is suggesting an edit soon after initial posting a discouraged behavior? There isn't really any direction for that outside of this discussion, and even here we seem to be split. The intuition seems to be "no, worthwhile edits are worthwhile no matter when they are made," but in practice the system of community-based evaluation seems to work better if the answer is "yes, wait a few moments for the OP and the community to assess it."
I would like to see continued discussion on the topic, since it seems there isn't quite a consensus on it. Thanks everyone for your feedback!