php warnings when using Capabilities

I have installed the Capabilities plugin because I want a few users to have the ability to edit the KB/Wiki articles.
It works great – set up a role, gave the role access to the kb/wiki actions and the upload media — and they can see those options.

However, I have two problems…
1- When logged in with the wiki_editor role, I see the following php errors across the top of every screen in the admin (as you can see, I use the Easy Testimonials plugin).

Warning: Undefined array key "edit.php?post_type=testimonial" in /.../easy-testimonials/include/settings/testimonial.options.php on line 1040

Warning: foreach() argument must be of type array|object, null given in /.../easy-testimonials/include/settings/testimonial.options.php on line 1040

Warning: Cannot modify header information - headers already sent by (output started at /.../easy-testimonials/include/settings/testimonial.options.php:1040) in /.../wp-admin/includes/misc.php on line 1438

Warning: Cannot modify header information - headers already sent by (output started at /.../easy-testimonials/include/settings/testimonial.options.php:1040) in /.../wp-includes/functions.php on line 7137

Warning: Cannot modify header information - headers already sent by (output started at /.../easy-testimonials/include/settings/testimonial.options.php:1040) in /.../wp-admin/admin-header.php on line 9

Warning: Cannot modify header information - headers already sent by (output started at /.../easy-testimonials/include/settings/testimonial.options.php:1040) in /.../wp-includes/option.php on line 1715

Warning: Cannot modify header information - headers already sent by (output started at /.../easy-testimonials/include/settings/testimonial.options.php:1040) in /.../wp-includes/option.php on line 1716

2. I use the Social Link Pages plugin. However, I can’t see any way to restrict the wiki editors from accessing that plugin. Regardless of WHAT capabilities I grant or deny, then user ALWAYS has access to the social links page.

The page I need help with: [log in to see the link]