Yes, you can still edit an article even though it was published in a publication owned by someone else.

It would probably be nice to give the editor a heads up, but as to whether or not it’s a good idea to make these small changes, I’m not sure.

Stories tend to get the most attention in their first day or two days after it’s been published, but that doesn’t mean it’s impossible to get a second wave of readership later down the road.

Hope this helps!