The whole issue of editing posts is currently being discussed at a Stack Exchange 'site wide' level.
Just hours after this question as asked, Stack Exchange introduced the second of potentially many new features and processes in the Suggested Edit workflow (I consider the first to be the auto-convert-to-wiki process of many-times-edited posts being removed).
Part of the revised attitude toward editing is that editing is actively encouraged, "... while ensuring that truly helpful edits – even small ones – are more consistently approved."
No more "Too Trivial" Reject reason!
The new workflow, introduced hours ago, no longer has a 'too trivial' reject reason. The threshold is now: "no improvement whatsoever", which is a lower threshold.
It is my feeling that the current thresholds for what is considered to be 'too minor' needs to be revisited. Fixing typos and spelling mistakes in posts (no matter how old), will lead to improved quality over the site, improved visibility for questions that matter (why were you looking at the post if it did not matter?), leading to more eyes-on-code.
The abuse-side of editing - editing just to bump, or vandalize, or spam - are still managed through the review queues, and still managed by the increased visibility (bumping) of the post. The downside is easily controlled.
I think a new attitude toward editing, suggesting edits, and approving edits is in order.