I am thinking your worrying about nothing.. when I create HOA's for my new communities I never turn them over to the owners until I am done building 100% of my project out.. last  thing you want to do is answer to a bunch of homeowners :)  then they set up their committees and they make sure everyone keeps the property in good condition etc etc. 

well your description of the situation is not complete.. do you know its landlocked.. somehow if there is a home there I suspect it is not.. but it does happen I am in a landlocked case right now been two years fighting it thankfully I have title insurance and they are paying the lawyers.. first thing you do is not rely on your own due diligence if your not a surveyor or familiar with maps etc.you do one thing first .. you order a title report.. you may have to pay for it.. say 200 to 250.. your probably in a title abstract state. ( not sure but most of the NE is)  the title company hires an abstractor to do the court house work they will then write you a title commitment.. if your TRULY landlocked there will be an exception IE they wont insure access.. if this is missing then you ask them to clearly denote on the plat map where the legal access is.. you then take that map and see if it works on the ground.. 

It’s located in my home town, and it truly is move in ready, the homeowner has lived there for 25 years and VERY meticulous about fixing or repairing anything that needs done and she has kept an extensive journal of anything that has EVER been done.

Like I am avoiding condo prop for big mgmt fees and costly insurance.

Like most real estate agents, most title companies are in the business of doing mundane transactions of a homeowner selling a house to another homeowner. 

. $5000Total investment: $30,480Mortgage payment: $530/month (Conventional 30yr at 4.6%)Annual rental income: $21,000Annual Expenses:  Property tax  $1200 (verified through property appraiser website)Insurance $1,200 (best guess)Prop man.$1,680 (8% of rent)Mortgage $6,360Calculations:NOI = Income (minus vacancy)- Expenses (Prop tax, insur, and Prop mgt)         = 21,000- 4,080          = $16,920Cash Flow = NOI - Debt service (mortgage)                  = 16,920 - 6,360                  = $10,560ROI = Cash flow/ Investment basis       = $10,560/ $30,480       = 34.6%Cap rate = NOI/ Purchase price                = 16,920 / 129,900                = 13.0% Cash on cash = ???

In Q2, due to occupancy levels, annual insurance premiums, annual property taxes, there was no cash flow above operating expenses and 8% is accumulating and will (hopefully) pay out in Q3 next month.

Besides the up front cost of the offered purchase price, title insurance, the tax bill, and annual property taxes, what other potentials costs should I be aware of (also mention any negatives to be aware of).Thanks in advance.

You have to do an analysis of what the cash flow is taking into account - mortgage loan and rate, insurance, taxes (High in some parts of Texas) Vacancy, repairs, cost of processing applications, showing, writing up leases or paying property management to do it.   

You will still have to hustle to acquire tenants, get them to pay rents consistently, then out of those profits, you still have to deduct vacancy factors, maintenance, management, taxes, insurance all of these items will affect that 10% hypothetical return.