Bootstrap row and col explanation

Answer 1

"Do I need a new row every 12 columns?"..

Contrary to popular opinion, it is okay to have columns that total more than 12 units in a single .row. It simply causes the row to wrap. This is known as column wrapping..

"If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line"

So this...

Is functionally the same as...

Having more than 12 columns per row is a common scenario when creating col-* dynamically. If you're having a problem with gaps in columns of different height you can use a CSS clearfix every n-TH column like this.. http://www.codeply.com/go/J6cCo3xL7H