Q:

relative clause including prepositional phrase

You don't want to throw out all that equity you have with your current audience.

I think a relative pronoun which or that is understood to be between "equity" and "you" , but was omitted to make it concise, but I'm not sure if I am correct.  
So the sentence originally is :

You don't want to throw out all that equity which/that you have with your current audience.

The relative pronoun "which/that" will be the object of the verb have,
and the relative pronoun "which/that" is equivalent to equity.
and the PP phrase with your currect audience can possibly be attached to the main clause or the relative clause, but in this case , it should be attached to the relative clause, as it makes more sense.
Are my knowledge above correct?

A:

I agree with you. 
Note however that knowledge cannot take a plural verb ('are'). I would say "Is my understanding correct?" or "Is my analysis correct?"

