I would just use rentredi to screen tenants and collect rent payments. 

They have lots of little fees built in, so I'm curious if those are also on the back end as well:Return to collect rent again Fee x3: $30Phone call with tenant fee: 8 minutes. $5 + .50 per minute.etc

There are a lot of hungry rookies out there that will collect a "Broker fee" or have you pay for a LOI (letter of Intent) and it's nothing but a piece of paper.

So, likely the HOA would not even collect any money unless the mortgage was small.

I am now summarizing the key points for managing rental properties to build my systems before launch ( I am strongly considering Rent-Redi software) but I am wondering how I would use this software for client's properties when collecting rent, holding deposits and the like.

Haven't heard that term used for data collection/skip trace.

I guess you could collect an illegal commission if the sellers and their JV partner were willing to pay it. 

This means to focus your time in the areas that have the greatest value & impact such as how to scale your portfolio vs working in the weeds on things like property management, repairs, rent collection, etc. 

You can only collect rent from one person at a time, so if the old tenants rented it until July 31, but move out (and have paid rent) July 15, you could (with their permission) let the new tenants move in July 21. 

What is the best all-in-one property management software that includes tenant screening, applications, rent collection, maintenance requests, etc.?