An elder is just a member promoted by either the Leader or Co-Leader. Like the Leader and Co-Leader, an Elder can invite other players to their co-op as well as dump tasks in a regatta. You can find out more about the member roles thru the Township's Setting button (looks like a gear cog)--Settings > Help and Support > Chat and Co Ops.
You can view more information on Co-op ranks on the Co-op page.
I like how it's set up now, you have a time limit and if something happens to you it doesn't tie up the task permanently for everyone else especially if some can get it done quickly. It's a team effort...
Task requests are great but to save them for 12 hours is way too long for a member that has certain items ready to go will slow down the Regotta, especially when you’re using a double farming, ie, silk, already to go. Maybe 2-3 hours only. Also, why does the game allow you to build up your barn and then take it away when the special is over, it is very annoying when this happens because you have to dump over 100 products that took you hours to FARM.