How complicated is this going to get? Are you going to model infections and gangrene after bullet wounds? It seems strange to have such a focus on nutrition...but then have a character be shot up multiple times and walk away

This is excellent work, just worried that the mod is going to become very, very complicated.
Thanks. Trying to memorize all of the rules or anolyze the code to figure it all out would be complicated, but the realism makes the mod itself intuitive. Everything is based on real foods and real nutritional models, so if you follow real life guidelines you should be OK. Calories and Hydration work more or less the same way they do with hardcoe mode, eat or drink more when they're low. It's the same for protein and nutrients - meat provides protein, veggies provide nutrients.
As for diseases and injuries, when I originally made Imp's More Complex Needs, it was made to supplement Real Injuries/Primary Needs and its more recent patch, RiPnO. FWE also had its own version of that mod's injuries overhaul, so making my own didn't really seem necessary. There doesn't seem to be much out in that vein for New Vegas yet though, so maybe I'll give it a shot. I'm sure I could come up with something.
@Krhanol
It's a little complicated to explain the "rules" of the sleep code, but if you sleep the way most normal people do you'll avoid penalties. If you went to bed before 12 and slept for 6 hours, you woke up before 6. The downtime lasts from 1 to 7, at least until your sleeping habits have readjusted, meaning you woke up too early. In addition to being asleep at the right time, you'll also need 8 hours of sleep per day to keep your sleep debt from building up, so if you sleep from 11 to 7, or from 1 to 9, or anything in between, you'll be covered - no exhaustion related penalties, and no "past your bedtime" penalty.
The only really complicated part is some new code that makes your character's internal clock adjust to their sleeping habits. The hour that you wake up every time you sleep gets averaged with your current wake up time, so over time, sleeping in or waking up early will make that wake up time later or earlier. It takes time though to go from being a night person to being an early morning person, just like it does in real life.
Regarding the missing water and out of place food poisoning, I've gone over the code multiple times and there is nothing that could explain it, so I'll have to wait until it happens to me before I'll have any chance of figuring it out.