For the file uploading not working, we don't have any limitation on that and if you were successful in uploading 5 files, you should be able to upload more of them. Maybe your hosting company is limiting the hard drive space you can use on your website and you reach the limit ? Or maybe you switched something like the FTP layer of Joomla or the "secure upload folder" of HikaShop and HikaShop don't have anymore the right to write in the secure upload folder ?
You can probably tweak the listing of files with some CSS. However, I need to be able to access the order on your website to be able to tell you precisely how you can do it (so I would need a user access who already made an order).