Select & DRAG

List of questions I have in my mind

Table

1. In a table should the selection should happen on mousedown or on click (mousedown followed by mouseup) ?
2. Provided the mousedown selects the cell in table, should the next mousedown on same cell should clear the selection ?
3. How can we drag a cell in table ?
4. How can we drag multiple cells in a table ?
5. Should drag should select the cells or should it actually drag the cells?

Tree

1. In a tree should the selection should happen on mousedown or on click (mousedown followed by mouseup) ?
2. Provided the mousedown selects the node in tree, should the next mousedown on same node clear the selection ?
3. How can we drag in tree ?
4. How can a mutliselect drag happens in tree ?