I wrote a couple custom browsers for both pro and personal reasons. I found out that there is a tiny niche market for a privacy-focused, minimalist browser that a) does not understand cookies, b) executes JS only when allowed to and c) is capable of displaying most decent Web sites without garbling them. I had good success with using Chromium as backend, and slowly adding the stuff we do need (download manager, password vault, auto-complete). Turns out it's quite easy to setup, but there's one annoying chunk: dealing with creating tabs or new windows. 'Modern' Web sites use and abuse that mechanism to display pop-ups, and it's quite a challenge to handle. Good luck to ya!