I'm practicing anylyzing deals but am wondering, when someone says a house is in a "B" or "B-" neighborhood, how to they come to that conclusion or where do they go for that info?

The key here is (1) the seller is motivated ( desperate ) enough to give up control of his property to someone who has little if any capital invested, while receiving no money upfront himself and still maintaining liability on his mortgage, and/or (2) the seller is convinced that you will be successful AND that his risk is small AND that he will receive future benefits.

Now you have a purchase contract and all supporting paperwork showing $450k purchase price.In practice, a first time rehabber isn't going to turn a property around in six months anyways....

Unless you invest via an LLC owned by the IRA, you will not have checkbook control over the funds which means you need to run transactions (e.g. income, expenses, etc.) through the trust company who will need time to process the transactions and generally charge fees for each transaction.

As a first timer, I have tons of questions on what to expect price wise, and how to do it especially since the property has central air so I have to separate the system into different zones for each apartment to have their own control and for billing purposes.

The fees and involvement of the Self-Directed IRA custodian can be significantly minimized by investing your IRA funds via an LLC as you will have checkbook control over the funds. 

Many people think this is standard practice and just go on ahead.

I have been in this industry for a long time and helped a lot of turnkey companies with best practices. 

Even though in some places one organization collects taxes for multiple taxing jurisdictions....for example the county may collect for, the county, the city, the school district, the hospital district, the community college district, the water supply, the noxious weed control district, etc, the individual entities may have lists too they would give you.   

My husband and I were looking for commercial real estate office space that would allow my medical practice to grow.