Problem retrieving informations and displaying desired structure with custom post type and taxonomy

For question 1, use a custom field when you create the page and use the same template each time. Here is an example using a custom field named house_type.

<?php

// Template Name: House Type

[ ... ]

$house_type = get_post_meta( get_queried_object_id(), 'house_type', true );

$args = array (
    'post_type'     => 'house',
    'orderby'       => 'meta_value',
    'house_type'    => $house_type,
    'order'         => 'DESC',
    'posts_per_page'=> -1,
);

Ask the other two questions as two separate new questions. It is easier to find 3 people who can answer one question each than it is to find one person that can answer all 3 questions.