It's a common scenario to set custom css on <td> for specific column, for example, using columns: { field: "ScoreNumber", css: "right-align", title: "Score" } to get <td class='right-align'>, then I can make every every score field text-align: right.

Maybe adjusting _tmpl: in Grid Widget as 
rowTemplate += "<td" + (column.css ? " class='" + column.css + "'" : "") + ">"; is a easy way to accomplish it.

It would be nice to have the possiblity to toggle edit mode on and off for the Grid.
Use case: Often users find things that need changing whilst browsing data. In those cases it would be nice to have a toggle button in the toolbar that enables and disables edit mode. n quiting edit mode the users

include checkbox-based selection in the grid and allow the persisting of selections in paginated grid (i.e. user selects rows on page 1, switches to page 2, returns to page 1 --> previous selection is restored)

with grouping/sorting/fixed wrapper size + prevent default select

http://www.kendoui.com/forums/ui/grid/local-virtual-scrolling---my-changes-grouping-sorting-works.aspx

My changes: 
http://oskar.doppnet.com/kendo-grid/local.html
http://oskar.doppnet.com/kendo-grid/remote.html