However, I’m looking for tools to help me analyze deals, particularly for multi-unit properties.

There are a ton of tools and resources that not a lot of people know so doing some YT watching and their training helps immensely. also, happy to answer any questions you might have on set up / operations.

You have to go with what works for you but please be sure your software or research tools are not erroneously bending into what you wanted to result to be. 

A financial advisor with real estate experience can help you plan effectively.

The sooner you regain control, prove that you fully intend to enforce the terms of your lease, and that you will not be 'played' by their recall of events or documents, the more effective this action will be.  

I started with the Simple Start plan, but as I learn more about the software, I realize that to effectively classify income and expenses per unit, I need to use Classes and Locations, which are only available on the higher-tier plans.I’ve seen suggestions to use units as customers as a workaround, but I’m curious if anyone else has tried this approach or has recommendations for managing multiple units in QuickBooks with the Simple Start plan.Looking forward to your feedback!

I don't want to get lazy (in the beginning) and rely on automated tools.

Leverage is one of the most powerful tools in real estate investing.

Do you have some tool for determining the median credit score for a given neighborhood?

I utilize a PO Box as well.It wouldn't be hard for our tenants to find out where we live (tax assessor's online tool) ~ But for $50/yearly ... it gives me a bit more piece of mind :)