Drop Rate related to monster life?

That's assuming your RNG is completely time-based.

If Maple's pseudo random number generator were flawed in such a way that the next RN generated from, say, a low RN statistically tended to be a high RN, then bait scrolling could actually be true.

That would require you to know
1. the algorithm the RNG uses: this isn't too hard, I think there's a standard RNG used.
2. the seed: next to impossible to determine
3. exactly what causes the server to generate a random number: probably a lot of things besides scrolls