Iḿ nice and fair by nature but like someone said earlier, I take the middle of the road approach.

The better approach is to specifically market to those people who would be good candidates for seller financing, and then make a deal from there.

No one starts investing with the perfect set of criteria and analytics.

What are key approaches I need to have when doing this? 

I had purchased a building in 2009 in the Old West End and I was standing outside when a man approached me saying he owned a 45 unit apartment building with a 30 car parking garage across the street that he wanted to sell to me.

If they had a verbal agreement with the last tenant,   and the last tenant gave notice or has officially abandoned per definition thereof  (you can look for things like them having cancelled their utility accounts, emptied unit of their belongings, etc)  then they can't prove anything and maybe you can use that approach.   

I'm noob and just building my own goals so helpful to see other approaches.

Sounds like you are approaching "Hurt City".

Learning what IRR is — and isn’t — will help you improve your analytical ability when it comes to making investments in commercial property.IRR is quite popular as a way to measure investment performance.

I completely agree with the business hours approach to repairs.