I could hire out structural modifications to add needed egress windows and strengthen the shear walls and rough in the breaker panel,  then frame the place myself, pay somebody to drywall it,  then install the kitchen and bath stuff and probably have a unit ready to go for someplace around $50K.   

The dirty AC ducts and breaker panel were additional items for negotiation sake that ended up sticking since seller likely didn't know they were issues. 

Deal breaker for me. 

I guess I'm reaching out to see 1) are the items listed above deal-breakers or 2)  how people analyze time involved in a project even it cash flows as your mindful of wanting to buy another.

Sure.... do I think its a deal breaker to be a good real estate agent... hell no...Do I think the bar for getting a license to sell people the most expensive purchase they will ever likely make is too low ?

You are not allowed to 'double dip' and if a tenant breaks the lease you have a duty to make every effort to re-rent and the lease breaker may only be charged for your actual losses and you'll be lucky if you can collect at all.

But having a bad credit score is not a deal breaker. 

It shouldn’t be a deal breaker.

Big pipe (monkey) wrenches, with a breaker bar, go slow, then install the new ones with the white pipe dope you can buy at the big box store. 

The deal-breaker is always when they want to meet in person.