For post snippets, pls see if something similar to the below should work for posts as well as custom post types like portfolio –
[show_post_snippets number_of_columns=3 post_count=6 image_size='large' show_meta='false' terms="inspiration,technology" taxonamy="category" post_type="post"]
For hiding the categories from the main blog, will post the code change you need to make in a day. Thanks for waiting.