1) It depends on your bios version, if it has settings to switch off Secure Boot then do so. You are probably far better off switching off Uefi as well if you can, it serves no purpose except to complicate things. If it doesn't have these settings - and some don't - then life is much more difficult.
2) If you have a flash card reader just unplug it from the video recorder and plug it in to the computer. Mint should be able to read it without too much difficulty (unless it uses some strange filesystem for storage).
Fujitsu Lifebook AH532. Intel i5 processor, 6Gb ram, Intel HD3000 graphics, Intel Audio/wifi. Realtek RTL8111/8168B Ethernet.Lubuntu 13.10,Ubuntu12.10 (Unity), Mint16 (Cinnamon), Manjaro (Xfce).