What would be great is a skeleton setup (no styling, just the raw output) where I can then wrap whatever sillyness layouts have been provided to me.

Sorry, bit of a rant.

and here, it still under construction but it gets you an idea on filter hooks etc..

http://docs.wpgeodirectory.com/codex_project/geodirectory/

If you need something in the specific, you can ask and we’ll do our best to help you out

Using Theme COmpatibility screen:

Options here allow you to change the wrappers and make any theme compatible

Using Filters:

There are several filters throughout the code to hook into targeted part of the output of all pages: http://docs.wpgeodirectory.com/codex_project/geodirectory_filters/

Actions:

Each template is broken down in several actions.

For each do_action, you will find a corresponding create_action in geodirectory_template_actions.php

In the create_action you will find the name of the function that is responsible for that part of the output.

If for example you want to modify the output of the listings/category pages you will open geodirectory-templates/geodir-listing.php and see that the action we need is :

do_action('geodir_listings_content');

we will search for geodir_listings_content in geodirectory_template_actions.php which will bring up:

add_action('geodir_listings_content', 'geodir_action_listings_content', 10);

on line 1786

Now you have the name of the function: geodir_action_listings_content (which is normally few lines below, like in this case on line 1792).

function geodir_action_listings_content()
{ //function here }

All you have to do now is :

1) copy the entire function in your active theme functions.php
2) rename the function to something like : my_geodir_action_listings_content
3) edit the function as needed
4) remove the original action :

remove_action('geodir_listings_content', 'geodir_action_listings_content', 10);

5) add the action back calling your customized function:

add_action('geodir_listings_content', 'my_geodir_action_listings_content', 10);

If you are developing a custom theme feel free to add Stiofan to skype for advise.