One of them sent theirs with the following info:Under Description of Operations/Locations/Vehicles:Blanket Additional Insured/Blanket Waiver of Subrogation/Blanket Primary and Noncontributory/Blanket Per Project Aggregate.What does the above mean?

In most recent cases, buyers are STILL purchasing properties with similar situations especially since inventory is so low.Assuming property location has decent demand AND your home is priced strategically when it hits the market, I'd say you do not need to obtain permits/COs.Are there any violations, open permits or complaints associated with these additions to the property?

Be intimately familiar with it or find someone that is. 6.Buy umbrella insurance to CYA. 7.If you do not hire a Realtor and are not familiar with contracts, hire a lawyer to look over.8.Make sure your credit score is good and you have liquid assets for more than you think you need. 9.Talk to an investor friendly lender to get familiar with the types of products. 

Apartments.com is also where I have tenants fill out a background and credit check, set up automated rent payments, and upload renter's insurance.

With a good LTV ratio (solid amount of equity) and decent credit score there will be some options, although it will be limited because of how much is going on, on this property.

I'm a few days from closing and when the title company sent out the settlement sheet with the security deposits and prorated rents as a credit to me from the seller my bank went crazy.First they said I need an addendum stating that the seller is crediting me.Then they said I need an addendum nulling that addendum because the seller can't give me that as a credit.

Local credit union.

Some counties OR cities now have additional registration requirements.  

I have 720-760 credit and almost 25k in assets.

These typically are not reported to credit bureaus and also do not affect your debt to income ratio which frees up your credit for personal loans that you may need in the future as well as does not limit you to the amount of loans that you can have as a buy and hold investor.