Problem:
Conditional filters on search view - how to show/hide specific filters based on the checkboxes option selection
Solution:
You will require to add the custom javascript/jQuery code with view's frontend javascript event js_event_wpv_parametric_search_results_updated.
Problem:
The user would like to preview a content template with a different post that the 5 posts on the preview selection dropdown.
Solution:
The preview selection dropdown is also a search box, just start typing the title of the post and it will appear. It is limited to 5 posts, you will need to have distinctive names to match the search. This will work for draft posts too.