Problem:
The issue here is that the user wanted to hide his filters that won't produce a result on their view.

Solution:

Assuming here that you are using a Blocks setup for your view then you wont be able to do it from here as this setting isn't available for the Blocks view setup.

You can only have this option when you're creating the view using the classic editor.

If you're not using the classic editor you can enable it by going to Toolset -> Settings and scroll down to Editing Experience and enable the 3rd option.

Once you've done this you go to Toolset -> Views to create your classic views.

On your classic view you will scroll to the Custom Search Settings then select "Let me choose individual settings manually" then scroll down to "Show only available options for each input" and from there you can select Disable instead of Hide.

Problem:

The problem here is that the custom fields are appearing on every post type.

Solution:
If you go to Toolset -> Custom Fields and edit your field group, under Appears On you should be able to specify the post types that the custom field group should appear on.

This should allow you to resolve the issue and restrict your custom fields to only appear on one post type.

Problem:

I am using the cred_form_validate hook to force mandatory taxonomy fields.

Solution:

Since the taxonomy field value is an array, you can check the first item of array value, for example:

https://toolset.com/forums/topic/unable-to-make-taxonomy-mandatory-even-with-suggested-code-in-php/#post-2145345

Relevant Documentation:

Problem:

How to add custom class or ID to the content template.

Solution:

If you are using blocks editor, you can try Toolset container block, see our document:

Relevant Documentation:

https://toolset.com/course-lesson/container-blocks/

Problem:

All pages content templates field is set to templates dynamically assigned by toolset.

is there a way to put it on none for all the pages ?

Solution:

You can try these:

Dashboard-> Toolset-> Content Templates, in column "Used On", find that content template which is assigned to post type "Page", remove it(or resign it from post type "Page"), and test again.

Relevant Documentation: