Need to know whatever you know about Chromium Development

Hi if you have ever made a chromium/brave based browser I would want to have a video call with you to learn about chromium and here are few questions I am curious about: 1) can we make modification in chromium for once in source code and make its installer for all (major) platforms (win, mac, Linux, android, iOS) and if so how can I? 2) how to get the stable build code, (no developer build or experimental features) 3) how to make a good chromium based browser's installer 4) how to develop APIs for chrome extension 5) how to install preinstalled extensions in chromium 6) ideas about making a good auto installer like chrome has if you KNOW any question's answer please reply. I am waiting for your msg. I will be very much thankful to you if you reply