1. You should NOT have to reformat your 4GB card to make it work on your Pearl...as long as the Pearl OS supports that size card.
Read this link for more info.. What type and size Media Card can I use in my device? - BlackBerryFAQ
2. When you plug your Blackberry into your computer, you should be able to have it go into "Mass Storage Mode". That will make it look like another drive to your computer. Just copy the files off using Windows Explorer to a Folder on your computer.