Recovering data from hosed phone
Since your data is so important to you, don't flash anything else until you do the following.
If you have data on a removable SD card, take it out! Get an SD card reader if you don't already have one and make a backup of the SD card contents on the PC. Also, leave the SD card out of the phone until you get it working. It could either be part of the problem or something else to get hosed.
See if you can use adb to get the data off while the phone is booted into recovery.
Make sure the phone has been on a charger for a couple of hours (data cable do charge, but slowly).
Using the latest supported ODIN for your phone, try flashing an Android 4.1 stock rooted rom (to avoid KNOX bootloader), and the newest Clockword Mod recovery and the newest modem. Boot the phone up (hopefully it works), update PRL and profile, don't update anything else, and then you can flash your preferred ROM. No flashing stock ROMs that are 4.2 or newer, risk of getting KNOX bootloader which you DON'T want.