This book was written by one of my favorite programmer bloggers. His blog javascriptissexy.com is sincerly a consistant reference for me. Don't knock it until you've read it.
>WebKit is a giant open source project that is relied upon by many many different companies...Google takes their ball and goes home and only works on their own platforms.
Blink is open source, it's simply a fork of WebKit. That's why Opera is intending to use it instead of WebKit2. It's like Google wanted to take their ball to another court and still let everyone play.
You will not be able to install multiple versions of Firefox side by side. You'll need to use Firefox Portable Edition if you intend to have multiple instances.
My rates and procedures are the same. Although, when clients expect me to rush design/build their work I bill 1.5 or double depending on the time frame.