Hello Megan,
Thank you for writing. You can remove the column header by accessing
EditorControl property and setting
ShowColumnHeaders for MasterGridViewTemplate to false. About setting the DropDown size, you can use
MultiColumnComboBoxElement, please, consider the following code-block:
Hope this helps. Do not hesitate to contact me again if you have other questions.
Sincerely yours,
Martin Vasilev
the Telerik team