i.e 500k (400k building+100k land cost),  with cost segregation average 400k X 20% = 80kcan 80k deduction be applied as depreciation, against his w2 income from a salaried position? 

Thoughts on the cost of this? 

It is a common practice and comes at no cost to you.I would also recommend you require your tenants to get tenant's insurance and add you and your property manager as additional insured as well! 

Leaks can be easy to fix or very costly to fix.  

The only payment you should accept is 100% in full, including late fees and court costs, and it has to be in certified funds (cash, money order, cashier's check).

You know, I always think that is very misleading when they charge thousands of dollars to newcomers base off marketing that boasts getting into real estate with no money down.These deals cost money. 

Can try to reposition to Class B, but neighborhood may impede these efforts.Vacancy Est: Historically 10%, but 15-20% should be used to also cover tenant nonpayment, eviction costs & damages.Tenant Pool: majority will have FICO scores of 560-620, many blemishes, but should have no evictions in last 2 years.

All that does is cost you more money. 

Along with many others I'm sure, I read "The Book on Estimating Rehab Costs" by @J.

I'm afraid skylights might leak or increase the cost.