To keep track of the History, Just references this in the WebBrowser Document complete or Webbrowser Navigated Events:
Code:
WebBrowser1.Url.ToString
As for the Textbox/Toolstrip resizing, you need to use Anchors.
Click here for Anchors help

For the bookmarks, just type this after deleting a bookmark:
Code:
toolbarname.Update()
Whenever you do a search, just put this in:
Code:
ComboBoxName.Items.Add(ComboBoxName.Text)