[Galaxy S 5 Q&A, Help & Troubleshooting] jsudekum:
TL;DR: My phone is in a bootloop. Attempts to flash back to stock or perform a factory reset haven't worked.

Originally posted on Reddit at r/AndroidQuestions and r/TechSupport. Please forgive me if this is an oft-discussed topic, but I've yet to find anything that's helped me.

A little background: I rooted my Samsung Galaxy s5 (Verizon) in August, 2014. No third-party ROM was installed; just root with Nova Pro, Gravitybox, and Xposed. I had no issues until about 2 months ago when my phone stopped rotating. It'd start rotating again after removing the battery, but eventually that stopped working, too, even in safe mode. I assumed I installed something weird, so I did a factory reset. That didn't fix the problem, though, so I intended to flash the stock ROM for a total reset. Earlier this week, my phone wouldn't connect to wifi. I powered off, removed the battery, and powered back on. And lo, le loop.

Solutions I've attempted:

1) Removing my microSD card. Didn't work.

2) Cache wipe. When I hold the power, home, and volume up buttons, I arrive at this screen. I'm not sure if I can get to the menu shown in the video. Factory reset and safe mode don't work, either. I'm guessing this is because I didn't set up a custom recovery? I'm honestly not familiar with CWM and TWRP.

3) Flash to stock ROM. I did exactly as this guide instructed. I put the ROM on the SD card, then flashed the firmware and kernel. Odin said it was successful and outputted this message (apologies for the wall of text):

<ID:0/003> Added!!

<OSM> Enter CS for MD5..

<OSM> Check MD5.. Do not unplug the cable..

<OSM> Please wait..

<OSM> VZW_BOC4_RETAIL_FIRMWARE_ONLY.tar.md5 is valid.

<OSM> Checking MD5 finished Sucessfully..

<OSM> Leave CS..

<ID:0/003> Odin v.3 engine (ID:3)..

<ID:0/003> File analysis..

<ID:0/003> SetupConnection..

<ID:0/003> Initialzation..

<ID:0/003> Get PIT for mapping..

<ID:0/003> Firmware update start..

<ID:0/003> SingleDownload.

<ID:0/003> NON-HLOS.bin

<ID:0/003> NAND Write Start!!

<ID:0/003> aboot.mbn

<ID:0/003> boot.img

<ID:0/003> modem.bin

<ID:0/003> recovery.img

<ID:0/003> rpm.mbn

<ID:0/003> sbl1.mbn

<ID:0/003> sdi.mbn

<ID:0/003> tz.mbn

<ID:0/003> RQT_CLOSE !!

<ID:0/003> RES OK !!

<ID:0/003> Removed!!

<ID:0/003> Remain Port .... 0

<OSM> All threads completed. (succeed 1 / failed 0)

<OSM> Enter CS for MD5..

<OSM> Check MD5.. Do not unplug the cable..

<OSM> Please wait..

<OSM> NI2_stock_kernel.tar.md5 is valid.

<OSM> Checking MD5 finished Sucessfully..

<OSM> Leave CS..

<ID:0/003> Added!!

<ID:0/003> Odin v.3 engine (ID:3)..

<ID:0/003> File analysis..

<ID:0/003> SetupConnection..

<ID:0/003> Initialzation..

<ID:0/003> Get PIT for mapping..

<ID:0/003> Firmware update start..

<ID:0/003> SingleDownload.

<ID:0/003> boot.img

<ID:0/003> NAND Write Start!!

<ID:0/003> RQT_CLOSE !!

<ID:0/003> RES OK !!

<ID:0/003> Removed!!

<ID:0/003> Remain Port .... 0

<OSM> All threads completed. (succeed 1 / failed 0)​

Upon completion, the phone just kept rebooting as it had before.

4) Flash to factory ROM. I downloaded the files for my phone mentioned in this tutorial, but they were in this format, so I'm not sure how to run this in Odin (which is looking for .tar, .md5, etc.).

IN CONCLUSION...

Thoughts? Opinions? Questions?

Did I make any mistakes when attempting the solutions above?

If you are collectively baffled, what are my options? My warranty is voided by my root, is it not? Is there an online service that repairs soft bricks for a nominal fee?

Thank you for your time.