1. You could probably use jquery to do that, though I haven't attempted anything like that yet but not a bad idea!
2. don't know.
3. Not sure what you mean by "classic paging" or "text input"
4. You could build your own paging controls to mock the bottom paging controls by inserting HTML into the type like so which inserts a checkbox with a label and sets the listener:
objTanksGrid.toolbar = {
items: [
{ type: '<label for="cb_2" class="right">Show Closed Tanks</label><input type="checkbox" id="cb_2" value="cb_val2" name="cb_tanks" class="right" style="margin-right: 5px;">', listeners: [{ click: filterTanks}] }
]
}