did a quick google and the audio issues are probably due to either normalization or formatting (I use vlabeler for my otos which is third-party software) so now I know what I should do. again, will deal with that another day and pivot back to other projects
I trimmed the audio to cut out any silence and I redid the oto from scratch but I'm still getting godawful noise on all the same notes I was before so I'm just gonna say this project is pretty much dead in the water - I'm not really utau-savvy enough to do any more than what I've already tried and yknow what it's just a jinriki bank anyway, I'd rather spend my free time updating and doing songs with my "actual" voicebanks. (Also when making jinrikis you're guaranteed a bit of noise and crustiness as it is, so I'm just gonna accept that it wound up being unworkable and move on.)