It was held by the previous owner for a very long time, so I wouldn't be surprised if some basic facts about the house are incorrect.I was making an offer on a house a couple years ago and discovered that the owner was paying taxes on an additional house that was on the neighbors lot and didn't know it!

What was the undisclosed permitting issue that the local flipper discovered from the public record?

@Ming HuangRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Cash-out or standard rate and term?

As soon as one violation is discovered, send a Notice To Quit advising them to stop/cure within your state's time mandate (mine is 3 days) or vacate the property.  

.✅ More Control – You’ll personally handle tenant screening, rent collection, and property upkeep, ensuring everything is done to your standards.✅ Stronger Tenant Relationships – Being involved directly allows you to build rapport with your tenants, which can lead to better communication and longer leases.Cons of Self-Managing❌ Time-Consuming – Dealing with maintenance requests, late-night emergencies, and tenant disputes can quickly become a second job.❌ Legal Risks – Chicago has strict landlord-tenant laws.

I am happy with them, I think they bring up value to investors, still I believe many of their deals don't meet my standards ( do your own diligence and run your numbers!). 

Here is the key: Don't pay for anything until it's done to your standard.

Pretty standard and we've definitely done it in the past with a lot of real estate agents we work with that invest. 

Studying real deals, using standardized models, and refining assumptions with real market data will help sharpen your skills.