Increase Categories section

Categories (and the other taxonomy area if used) all have min-width: 150px, where excerpt has min-width: 250px

You can add the following to your theme css:

fieldset.frontier_post_fieldset_tax {min-width: 250px !important;}

if it is important that they have the exact same with, you can assign same width to both by:

fieldset.frontier_post_fieldset_tax {width: 250px !important;}
 fieldset.frontier_post_fieldset_excerpt {width: 250px !important;}

Thanks for the prompt reply, but I want to increase the height of the Categories area? And is there anyway not to show the Tags section?

You can also increase the height using CSS:

fieldset.frontier_post_fieldset_tax {
width: 250px !important;
height: 400px !important;
}
fieldset.frontier_post_fieldset_excerpt {width: 250px !important;}

You can disable tags by unchecking “Edit Tags” in Frontier Post Capabilities settings.

I don’t see the Edit Tags checkbox. The only thing that appears in the Frontier Post Capabilities settings is Role based settings table

So you are managing the capabilities externally.

Then you need to remove the capability: frontier_post_tags_edit

See here: https://wpfrontier.com/frontier-post-profiles-capabilities/