ReasonImageLocationSnippet
I want to hide the toolbar completelyUI-Composer.fpd-element-toolbar-smart{display:none!important}

If you're using the old version of toolbar -
.fpd-element-toolbar
{display:none!important}
I want to hide the toolbar only for imagesUI-Composer
.fpd-element-toolbar-smart.fpd-type-image{display:none!important}

I want to hide the design previewUI-Composer.fpd-thumbnail-preview{display: none !important;}