Overriding panel/datagrid behaviour

[ThomasVague]

Hi, I was wondering something. I have a form like this:
datagrid -> container -> panel -> input fields.

So when it's filled out, it would be something like this:

datagrid
  container1
    panel
      input1
      input2
  container2
    panel
      input1
      input2

When I load the page is there a way to collapse all panels if there are more than 1 panel inside the datagrid or else if there is only one panel, show it as open? I've tried hooks and overriding behaviour, but I haven't been able to do it.

Second thing, when I click "add another", is there a way for all panels in the form to collapse except the new one?

And thirdly, instead of all the panels having the same title in the header, is there a way to add an increment value to each title?
Like: Panel 1, Panel 2, Panel 3 and so on.

Thanks in advance!