She was brave to share the unfiltered truth of her journey, I would suggest that you keep that in mind as you comment.   

Be excited, Be brave, and Be bold! 

I'm a full time web developer and have a background in design, and I've done two full live-in renovations (currently living in the 2nd).

Best advice I could give is get very familiar with navigating county web sites.

General question: outside of renting tools from a brick and mortar store, are there any web applications, mobile apps, or online marketplaces where people share construction/remodeling tools peer2peer (similar to turo, Airbnb, etc)?

Keep yourself organized and strive to continue to improve your agreements and always be brave and responsive with your tenants and your properties.

I can't say about Atlanta specifically, but generally you'll want to check the local municipality web site that the property resides in for any short-term regulations, as well as the HOA if the property belongs to one.  

I was wondering who might be brave enough to share any unexpected pitfalls/struggles that they encountered by being their own property manager of a multi unit apartment.As I began thinking about managing a multi-unit (especially one such as a 10-30 unit dwelling), I tried to think outside the box about possible unforeseen challenges outside of the typical calls "my sink doesn't work" or "my toilet doesn't flush". 

All my links are in my BP profile, provided you're on the web site and not using the wretched phone app!)

I was looking for a good deal in this web sites and the problem is that everything is renovated and overpriced.