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.

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.

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

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. 

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. 

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. 

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

So you too need to develop some reserve accounts - one for repairs, and also one for property taxes and property insurance payments - which are big expenses that are due once a year, but your seller will likely not collect like a bank might escrow for you.Know that seller financing gives you lots of options to negotiate your deal - but that cuts both ways.