[orophins]

1) You don't have to. Obviously if you don't, you're going to have a mess on your hands - even if you do, it's still fairly likely.
2) The longer you hold it, the more / messier you'll be, and the harder by far it will be to hold. Honestly if you hold for 24 hours you're unlikely to be able to get all the bananas in before having to put the pad in.
3) I would recommend using a pad because the "sticky" side can be wrapped into itself so that it holds together better. You can probably use a liner without issue if you roll it up tightly and can get it started - but I can't commend.

If you have any other questions, feel free to message me. I think if you've never done bananas or similar before, you may want to be ready to put the pad in before you've used all of the bananas. I would also recommend trying some of the components first to make sure you don't have bad effects (it would be an awful time to find out you're allergic to bananas, for example!)