So I and 2 friends created a TX LLC for the purpose of meeting a $100k minimum to join as Limited Partners of an LLC that bought a multi-million dollar, 200 unit apartment complex in Atlanta Georgia. 

If you are in LA City limits you can find a lot of good info here.http://zimas.lacity.org/And here.http://ladbs.org/If you are in County territory they have info online too.

From an ongoing management perspective, you want to know how to avoid prohibited transactions, calculate annual contributions, and process annual filings (if applicable) - among others.

Do I treat the existing tenants like new tenants and have them fill out an application just so I can have information on them?  

There are AGI limitations for contributions, but at $12k I wouldn't be too concerned about that.It may be worth reading IRS Pub 561. 

So I am wondering if there is a limit to how much your real estate tax can go up in a year? 

Here's something that may work for you: Some MLS systems allow brokers to enter what is referred to as  limited service listings (google "flat fee MLS listing" and you won't have any trouble finding one). 

I own about $4m in additional real estate which did come into play during the application process.

I myself dont own any properties so my experience is limited but sounds like a good deal to me.

Fire damage is not only limited to things you can physically see; it's also things you can't see.