John, edits are reviewed by a number of different groups. There are Google employees, RERs, and regular users that can all review edits. Depending on the nature of the edit, it may take more or less approvals to get fully published. As for time to review, I'm not sure how Google employees prioritize their reviews, but it can take up to a few days to be looked at, depending on their current workload. RER's are a different story, as volunteers, they do what they can. 24 hours is not an excessive amount of time to wait for a review IMO.
I encourage you to be patient, and you can always move onto another area if you are waiting for an edit to be approved before being able to continue. If you need a review urgently, as mentioned by Nuclear Moose above, you can start a post in the Review Edit Request forum and hopefully an RER can take a look at it for you relatively soon.
As for you second question, I guess it's up to you if it's time well spent. You are befitting your community by showing them where trails are so they can get out and get active. I think that's a noble cause, and I think that also answers your last question.