If you did any work without permits, stop now and go get the permits before you get a red card that will leave you on the sidelines for 6 months to a year.

In addition given the large DP I suspect you were not worried about a deep dive into the church's ability to debt service.. ???

Can you experienced investors share some insights on what factors are crucial to analyze and what red flags to watch out for?

I love the world of finance and investing, have always had good returns percentage wise, but nothing life changing as I have never had the free capitol to go deep into any investment.

It was a huge red flag, so we immediately changed our offer.Trust is essential in real estate, and if you don't trust the seller, walk away.This anecdote taught me significant lessons.

Anytime a tenant is nasty with our staff it is a huge red flag.

Last thing you want to do is get too deep somewhere with your time and money only to realize the STR laws are not friendly.

It is a very high cost of living and my landlord has been renting out the triplex for a little below market value for the past few years, however he is going to be selling the property ( all three units)  (This area is considered very nice and "shouldn't" depreciate in value. )I have been trying to deep dive into bigger pockets, reading bigger pocket books, watching videos but  a lot of the resources talk about multi-family properties as purely renting out all units and not actually living in one of the units. 

Just watch what tree you bark up, you could get the wrong dog.The cash balance you hold is great to hear, but how deep are you?

"Cannot" in this sentence as a red flag.