Question: How did blood drop reached Marta's shoes, even though it was too far from Christopher Plummer in the suicide scene? (00:53:50)
Answer: The rationale is that blood can travel quite far from an artery and her shoe therefore got the droplet on it even from the doorway - however it does seem to me that the filmic portrayal is lacking, since you don't actually see any instance of spray. Rian Johnson' script says "Blood gushes." What we see in the scene is that it is trickling down his cut - a bit.
Question: When police scour the old neighbourhood, there is a shot of a man wearing some kind of huge metal suit. What was this suit used for? (00:46:53)
Answer: Most likely protective body armour.
Question: How did the monkeys get onto the space ship and why were they so aggressive?
Answer: On the way from the Moon to Mars, the Cepheus interplanetary vessel receives an automated distress signal from a Norwegian bio-medical space station (that studies and conducts experiments on Earth animals in the deep-space environment). Apparently, a couple of very powerful and temperamental adult baboons escaped from their cages and killed everyone aboard the space station, feeding on their bodies. When the Cepheus answers the distress signal and arrives at the space station, the baboons attack and try to eat Captain Tanner and Roy McBride, also.
Question: How was Elijah getting out of his room in the first place? I know he has free roam of the facility after killing the guard and taking his keycard, but I don't recall the movie explaining how he was getting out earlier in the movie?
Answer: He's picking the locks on the doors, bypassing the keycards.
Answer: At one point, Elijah's mother mentions that he caught a glimpse of and instantly memorized a blueprint of the psychiatric hospital when he was first committed, and he used that knowledge to short-out the hospital's electrical system one time (before they started heavily sedating him). It seems likely that Elijah was able to somehow hotwire electronic door locks, using his knowledge of the hospital's electrical system. Later, he used a master keycard taken from the guard.
Answer: Not only that but, it was shown in the first movie that Elijah was very good at manipulating people so he could have convinced somebody to let him out.
Answer: The movie doesn't explain. But given what we know about Elijah from "Unbreakable" and this film, it's really no surprise he managed to find a way out - he's psychotic, but he's also a genius.
Question: Spoilers: When Simon's corpse is discovered flayed apart and hanging, it looked like some of the organs suspended above him (possibly his lungs?) were still moving a bit. Was he still alive at that moment?
Answer: Yes, that is the impression that is given. He is still alive.
Answer: To add slightly to the other answer, evidently some of the blood in the scene had to be digitally removed for the film to secure a PG-13 rating, which explains why we don't see any actual spray/gush. But we are to assume that a drop managed to splash onto her shoe when he slit his throat.
TedStixon