Typical breakout is usually 60/40 but depends on the property.

Depending on size of lot and # of structures and impervious surface these typically are not cheap

How long is the typical due diligence on a property like this?

Typically it breaks in hottest or coldest day of the year and that’s when you will pay a premium price to get it replace or fixed.Personally I would not want to install a refurbished HVAC system, I think you’re better off w new installation and not have to worry about it for a long time.Typically when I purchase a unit and I know HVAC system is over 15 yo I know that sooner rather than later I will have to replace it and I plan for it..

"Site control" (sourcing a new deal under contract) is typically one leg of the stool--the others are capital and experience (such as rehab & project management, etc.). 

I currently work as an engineer and plan on using income from my day job to finance downpayments for rental investments.I am interested in out of state investing as the cost to enter my local market (SF Bay Area) is a lot higher than I can afford and don't typically provide cash flow.

Typically, you are supposed to do a final walkthrough the day of or day before closing to avoid issues like the garbage issue you explained.

What is more typical is you being the guarantor on the loan and title being held in LLC name.

My criteria for buying are at least a 10% CoC return, and $100/month or more in net cash flow PER door (hopefully closer to $200/door).List Price:  $179,900Down Payment:  $44,975  (25% down, assuming I buy at list price)Repair Estimate:  $5,000Closing Costs:  $2,500TOTAL CASH IN:  $52,475Loan Amount:  $134,925Loan Terms:  5.25% fixed rate, 30-year mortgageMonthly P&I:  $745Monthly Rents:  $2,000 ($1,000 per side)Vacancy Loss:  $100/month (I estimate 5 - 8% on multi-family properties, depending on how popular the area is).TOTAL MONTHLY INCOME:  $1,900 ($2,000 - $100 in vacancy)Taxes:  $154/month (you can usually find the actual tax amount paid for the previous year on your city's website)Insurance:  $100/month (ask other investors in your area what they pay, or for recommended agents who can give you quotes)Water/Trash:  $80/month (this is typically paid by the landlord in my area)Sewer:  $50/month (also typically paid by the landlord in my area)Lawn/Exterior Maintenance:  $75/month (my property management company offers this service)Maintenance:  $100/month (people budget anywhere from 2 - 10% for this... if it's a well updated and maintained property in an area that attract responsible tenants, I budget on the low side)Property Management:  $100/month (usually 8 - 10%, but you can find PM companies that do it for less... just make sure they're good at what they do!).

I think if you have "boots on the ground" in place in NY and/or don't mind making the trip then you should take advantage of your knowledge of the local market.I am not sure where you are getting your list of apartment owners from, but I typically use a cheap postcard on my first mailer to "scrub the list".