1. Is the portfolio similar to the one used in Ally, that is, it’s a view of the blog posts, not a separate portfolio post type?
Yes it’s the exact same portfolio. It’s currently featured in all of my themes.
2. Is it possible to display the portfolio on separate pages by category, for example, using query_args for categories in the Custom Fields?
Yes you can do this, I have a tutorial here – https://appfinite.com/tutorials/how-to-create-multiple-portfolios/
