Can I flash the mk5 4.3 rom, I have knox and that rom is for people who dont have knox so wouldn't it brick my phone becuase it would modify knox? Is the 4.3 rom that is meant for users who haven't done the ota update compatible for me a user that had done the ota update? Is it safe the flash given I have knox, 4.3 mk5? If anything I just want to know if I can use it if I ever want to revert to stock kernel, it just seems people on this forum are at different levels.
OK, for starters, I would presume that you have read through the sticky threads very carefully, at least the OP of each. Lots of information there, that is why they are stickied. Britton does an awesome job maintaining his threads, and I try to do the same. So, to touch on your questions:
Anybody can flash JD's MK5 ROM.
Anybody. The upside to his ROM is that someone, like myself, who does not have the Knox bootloader (we call it "Knoxed up" now), can safely flash his ROM without fear of getting Knoxed up. Nothing that "modifies" Knox (it can't really be modified, it either is on your phone or isn't); what his ROM does, in conjunction with SuperSU, is put Knox in its place so that it can't bother you. You will never even know it is still on your phone, for all intents and purposes. The
ONLY thing that will cause Knox to act up is using Odin for pushing a .tar file meant to restore the MG2 or MD7 bootloader (bootloader is not modem, always keep this in mind; flashing modems is 100% safe if you need to try to improve your signal/data connectivity). Also, stay away from any advice telling you to try the MD4 bootloader from Sprint. Here is the current rule regarding Odin:
ONLY use Odin for pushing a
custom recovery. Period. If you don't already have Philz Touch installed, I would highly recommend doing so now, and then put Odin on the back burner unless you need it for another custom recovery (which you shouldn't once you have Philz). Knox
WILL F your phone up big time if you try to replace it with another bootloader, which is only possible via Odin,
NOT by flashing a custom ROM from custom recovery. Therefore, the answer to your question about available ROM's to flash: all of them. Do JD's first, get it running the way you want, then make a backup which you will never get rid of, because this will be your fallback stock ROM if you ever need it. I get rid of backups I no longer need to free up space as I progress through various ROM's, but I always keep his original file and two backups on my phone for a rainy day. After you have used that one, feel free to try anything from the OP of my CM 11 thread, I have already done all the dirty work of getting those ready to flash, as have several other users further on in that thread. Post number three in my tutorial has links to tons of ROM's on XDA as well, and a lot of them are upgrading to 4.4.x as we speak. There are also some pretty nice ones based on stock 4.3 as well, like M.O.A.R. and Static Power, if you prefer more of a stock feel. Basically the sky is the limit.
DO NOT fear Knox, just respect it and put it in the corner where it belongs! Let me know if you need further clarification, PM or post is fine either way.