Query Regarding Editing and Re-uploading a File

Focus less on old stuff. 

Instead, concentrate on creating good quality NEW content.

If it's pending review, go ahead.

If it was already accepted into inventory, leave it alone.

There's no guarantee it will get accepted a 2nd time by another reviewer.

 If I proceed this way, will it impact the file’s ranking or visibility?

By @Insaign

Sure, you will delete the old file and have uploaded a new file with no sales. If there is no issue with a good selling picture, and you just want to make it more beautiful because you are now more talented, don't do it. If you want to improve a bad selling picture, go ahead.

You will need to delete the old file. If you delete it after the new submission, that will be early enough. You are risking, however, a refusal on the new asset. So it's always a bit risky (for getting a refusal!), so again, I would not change a good selling asset.

If the revised asset is essentially the same in appearance as the first image, re-submitting might be considered spam or a duplicate. Also, if the first image has actually been licensed by someone already, it's best NOT to delete it.

I am not sure if it would cause an issue or not. Often accounts are closed do to "suspicious activity". I believe new submissions have a higher ranking than older files. Adobe may consider this a way of boosting your assets. I would not make minor adjustments.

"I want to update one of my uploaded designs by making minor adjustments to its layers and colors. Should I delete the current file, apply the changes, and re-upload it as a new submission?"

You can do this.

"Additionally, can I re-upload the design using the same title and keywords without causing any issues?"

It won't cause issues.