In future updates, can we also make an alteration to shop chests (if at all possible) to allow people who you designate to also get into the chests?

Like say I'm running a shop and one of my friends has a chest that needs restocking but he isn't able to play for a while. Could you alter it so that I can get in and restock it or does that power reside with the creators of the people who built that plugin?

In future updates of the auction, there will be town specific sides that list everything sold from residents of each town. So you can help support your residents/create a town market system.

That's cool. The possibility to have people chip in and keep track of transaction will surely help with big projects.