I'm currently considering eXp realty or century 21 for brokerage but I feel fairly new and not sure if I'll be to get the necessary guidance to help me properly negotiate and execute this deal.

As can expensive policies that don't properly link yours and GC's share of risk. 

If her cooking causes the smoke alarm to go off, then she is not properly watching what she is cooking and creating a fire hazard.

@Kamal Sharma That is a VERY tall order for the Bay Area proper.

It is easy to react quickly & fearfully when you get a letter from a lawyer threatening litigation, especially when it comes to land rights.

In other words, if properly run, it could be profitable to provide the sewer utility for a park. 

If you don't know how to, you'll need to learn how to properly value properties or find someone, like a local investor or real estate agent, to help you.

How can I get the HOA to properly fix (dig up and replace) that part of the sewer line?    

You can always walk away, but I don’t think that’s the proper thing to do.

Jumping in without proper knowledge is not wise.