Dynamic product catalogues
Personally instead if all Vocabularies are part of same "Tree" they should be in one "vocabulary" and current items should be displayed as parent terms -> children terms tree structure

1. regarding first bullet point


https://www.drupal.org/project/taxonomy_menu &lt;- allows adding
taxonomy items to any menu of your choice
https://www.drupal.org/project/taxonomy_menu_block &lt;- creates a block
in sidebar with list of your terms of selected vocabulary with
options such as "Count" that is updated on cron run
taxonomy_manager &lt;-  I use to mess around with the order of things or
importing lots of terms it really speeds up the process if you would
need to move taxonomies from different vocabularies into one :)
Google it as I cannot post more then 2 links :)


2. regarding second bullet point

For that you would need to create "Taxonomy view" instead of content view and set it up so that the categories would be displayed for example: (cant post example as not enough rep)