For the first part of your question even if you were working with a realtor, I don't personally know many that have a true pulse on rehab costs and I wouldn't make any investment decisions based on their rehab cost projections.My suggestion would be to study how to evaluate the Big 6 rehab costs: roof, siding, windows, HVAC, electrical, and plumbing. 

If it costs $500 to fill the oil tank and the tenant leaves it empty, that's $500 less you have to cover unpaid rent, cleaning, and repairs.

Roof Maintenance/Repair: Done as needed, paid by the owner.

There is usually one for each State/Couty and a few Government DPA's that will cover down payment and closing costs as well.

The biggest mistake new investors make is to walk a property, maybe explain in general terms what they want and then let the contractor come up with the SoW.For a bedroom this could be:- replace carpet- repair closet dooror- remove carpet- remove curtains, nails and screws- replace closet doors, entry door SKU#- replace window SKU#- refinish hardwood floors 144 sqft, clear/oil-based- prep and paint all woodwork- patch walls, texture, paint walls eggshell white clay, ceiling flat white- replace light fixture SKU#, replace lightswitch w decora/white, replace 3 outlets&covers- install blinds SKU#Obviously, the cost would be quite different.

Since your friend covers utilities, this offsets some of your cost.

What is a storm rips through and trashes the roof, BUT the condo project does not have enough insurance coverage to fix it, the value of the all the units in the project just went down. or, even if they are able to fix it but  the coverage premium doubles so the HOA has to double the monthly HOA dues but half the complex can not afford it? 

We are currently looking at a HUD home in Georgia - I have a couple of questions and can’t seem to find a definitive answer - The home is currently in the OO listing period - our plan would be to buy the home doing extensive renovations (the home is in a “Historical” area so renovations have to be approved) once completed we plan on living there full time - it could take ip to a year to complete or longer I don’t know  - as I see it the OO designation is to be the OO for a min of 12 months - is this after the home has been renovated or after you close on the home - though the house could probably technically be lived in now it does have some water and roof damage and needs complete redo of electrical and plumbing - for me to deem it safe - so not really livable by normal standards - but no way it would be livable in just a couple of months - any thoughts or an actual answer to the OO rules 

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 (approaching 22% probability of default), many blemishes, but should have no evictions in last 2 years.

This is very well worded, and I believe covers most new investors' concerns and questions.