Most of my freelance work is one-time projects, so I invoice half up front and half on completion.

I used Freshbooks in the past and really liked it, but am currently switching to PayPal as my invoicing tool. It's free (compared to $20/mo for Freshbooks), and does everything I need it to. tbh, I'm wondering why more freelancers don't use PayPal?

Super nice! The only thing I would do different is make 'Work' the homepage and 'Profile' the 2nd page. I set up my portfolio in a way that my designs would literally be the first thing the user sees.

I agree, my portfolio site purposely has no photo of me. Showing your face doesn't add any value to your site, in terms of getting a job or clients.

I love that it knew I came from Medium and assumed I'm a fellow designer

Here's a great article on what to include and what the goal of a case study is http://blog.invisionapp.com/how-to-design-case-studies/