It seems like you have two concerns: 1) Adding content, and 2) Seeing how
the book looks.
1) You can just as easily type in the code view window. Practically the only thing CV doesn't do that BV does is automatically wrap <p> tags around your paragraphs. That is easily fixed by highlighting (triple clicking somewhere in the paragraph - or clicking on the number to the left) the paragraph and hitting the "p" button.
All other styling functions (italics, bold, sup, sub, etc) work the same in either view.
2) Have you tried using PreView in your workflow??
You can use preview always docked to a side of the screen, or even undocked as its own window. You can resize PV to simulate any size device to check how the book looks and reflows... If you have a second screen you could even drag the window to it... You can even toggle between the two modes by double clicking the header - or hitting F10. The possibilities are endless!!
Docked to the right:
It's own window:
