Q: Exfat support

You will to re-format them so that they are not ExFAT, or use smaller cards which don't need to formatted as ExFAT - from http://support.apple.com/kb/HT4101 :

Here are the supported SD cards and image-transfer protocols:

• Picture Transfer Protocol (PTP)
• Mass Storage Device protocol
• SDSC
• SDHC
• miniSD
• microSD
• MMC
• SDXC (supported only when not formatted as ExFAT)

Exfat formatted sd cards (SDXC) now work in IOS 7. ;)