The macerator chops everything up into fine pieces, and then the pump sends it up to the gravity main.

I have followed that works well#1&2 almost have to be thought of as the same priority because its gravity dependent#2.

Use gravity flow for your drain line and you won't have any issues.

The owner is too stubborn at this point but soon will realize the gravity of the situation as the month of November draws nearer.

That's like breaking the laws of gravity!!!...

As long as gravity isn't the hindering factor then you should be good.

Next - you need to see what type of waste treatment will be required - this can vary from relatively cheap if conventional gravity fed septic can be used to CRAZY EXPENSIVE if an engineered system is required.

Either most don't yet understand the gravity of what has happened or they are laden with apathy is all I can figure. 

But I live in an area that always defies gravity in relation to "the national market."

Understand the gravity of this and do not think about the commission check EVER!