A Realtor would work for you, help negotiate price and terms and know which builders are offering incentives to you, have a good reputation and will be your advocate during the entire process.

The main thing to check first is builder reputation..

His primary mortgage was sold to a private lender in the early 2000s and he claims he had to give an explanation each time as to why he financed with a private lender with such poor reputation every time his credit was pulled.

Consequently, there are fewer commissions available for real estate agents.Secondly, there's the looming lawsuit against the National Association of Realtors (NAR), which threatens to squeeze the commissions that end up in the hands of buyer's agents.

Note that this can sometimes cause unexpected consequences.

Yes, but he/she could also face consequences (litigation) for defaming a person in writing (libel). 

It's in a reputable school district and sits on a .5 acre which is a lot for the neighborhood.

- loans against cash value are distributed without tax consequences?

Unless you are an attorney practicing real estate in the state of the subject property, the chances of reaching a wrong conclusion are too great and the consequences too costly.  

As someone who works for a reputable GP, I'd say there are a few key factors that weighed my decision to join the team.