Well, I'll tell you the things I want to research, and you can grab one of them if you want:
a) Dropping creatures on other creatures -- sometimes the falling creature gets hurt, sometimes not. What's the critical factor?
b) Build order with levers. Already did careful timing with pressure plates, want to confirm on levers.
c) Undead and vampires living happily together. I want to see if vampires can chain captured zombies, for instance.
d) Special attacks and pathing. Do deadly dusters need path to kill via dust? Do they still need the target to be on the same z-level to be affected? Will zombies do deadly dusts? Will FBs deadly dust through a distant fortification?
e) Falling through a hanging pressure plate. Will the plate get set off?
f) Merchants bit by werewolves. Will the eventually become insane if constrained, or will the werebeast status reset their insanity timer? If elven werebeasts, will they never die, thanks to transformation resetting hunger/thirst?
g) Werebeasts in cages. Will they transform?
h) How do undead path? What do you need to do to involve one in a creature logic circuit?
i) Can I make specifically offset delays using 2-step cyclic repeaters and manipulating build order, such that, for instance, a door might be open exactly 10 ticks every 100 ticks? (The answer is yes, but I have to do it to work out the practical part of it.)
j) More on syndromes. Am I correct in noticing that tiles are getting seasonally autocleaned now? Is it possible to design a contamination trench that won't get cleaned? Is clothing definitely a protection against contaminants, or not?
Ugh, I guess I have an infinite number of research questions. It's true, this is more ivory tower stuff, less practical, but if you're into any of it, try it out and let me know what happens