Ok, I may have figured out what went wrong. So, I went ahead and relocked my boot loader and ran RUU to get back to square one. I unlocked the boot loader and stopped myself...I noticed a subtle difference with TWRP versions for the HTC One. It seems like there's a difference - one is 126.96.36.199-m7 and the other is 188.8.131.52-m7wls. I have the Sprint model (the latter version), not the AT&T/etc. model (the former version). Once I did that, it seems like all went well.
That's what I get for not paying more attention to details. It's a heads-up for anyone rooting an HTC One, at least.
Thank you for responding.