I don't understand your code and you must be mising types here, as ListViewItem doesn't have the Dock property.
In any case, based on your text, I created a small demo application here. This application declares a UserControl with 1 textbox and then adds one instance to each of the ListView's three control type columns. Focusing on the first (leftmost) textbox and tabbing will get you to the next column on the right until you reach the far right, then focus is lost. We already have an enhancement request on that problem. Please view it here and follow up on our progress.
Hope this helps,