Problem:

Remove tces-js-style-encoded embedded CSS styles from content template.

Solution:

You need to design the post view and content template with classic editor, and display the content template with attribute "suppress_filters":

[wpv-post-body view_template="xxxx" suppress_filters="true"]

Relevant Documentation:

https://toolset.com/documentation/user-guides/views-shortcodes/#wpv-post-body

Problem:

I have already bought the 1 site toolset and installed on my existing website. I needed to test it first by installing one of the test sites.

Solution:

I suggest you try these:
1) Follow our document to migrate your existing website to another development website:

https://toolset.com/faq/how-do-i-migrate-a-wordpress-site-from-one-domain-to-the-other/

2) In the development website, upgrade Toolset plugins manually, you can download them here:

https://toolset.com/account/downloads/

Relevant Documentation:

https://toolset.com/faq/how-to-install-and-register-toolset/#registering-toolset-in-a-development-environment

Problem:

Using relationship API function toolset_connect_posts() in custom codes.

Solution:

You can follow our document to setup the custom codes.

Relevant Documentation:

https://toolset.com/documentation/customizing-sites-using-php/post-relationships-api/#toolset_connect_posts