4. meh it can be anything..
he might have died from thirst or maybe it's a heart attack or he died from hunger or he ate something poisoned or anything else..
i'd go with heart attack since he was clutching the straw, so he might have been in pain, it's a weird reaction to get a hold of something really tight , and there was that large dune so it might have been a lil too much for him
or if you want a knock knock style, it might have been the last straw
5. might be a murderer that doesn't want his finger prints around the elevator just in case someone saw him enter the building after he killed
but he might just be a freak, or maybe he is afraid of the elevator's up move and feels safer with other people
6. once again , alot of reasonable reasons:
a. he called you over
b. leaving the door open seems too obvious, if he wanted to suicide he wouldn't want you to be able to get in soon enough to possibly stop him
c. the gun was in his hand, normally the gun would have fall on the floor after suiciding, it's too obvious too
d. he holds 2 items at the same time, and he shot himself, you would expect at least one would fall
e. he wouldn't bring up an old taperecorder , it brings up memories, which would have slowed the suicide action down
f. you said you only hear his voice in the end so:
1. do you hear anyone else before?
2. talking about perfect timing , if you can hear the shot and it's the end it must have been perfectly timed to the end of the tape, which is impossible , he couldn't have pressed the stop button after he suicided
7. he didn't get an answer in the door, in other words the door was still locked, if so there was no break in, the window wasn't broken either, an inside job clearly, since no one else was around i suppose he was the single suspect, and thus got arrested.
also, the snow seems to have been very heavy, possibly the window was too iced/snowed to be fogged or to be cleanable.
possibly ,a lack of footprints of another person or of the neighbor to the back of the house
and lastly, i suppose any normal person in such weather would just give up instead of walking around trying to find that person...
(i doubt i got that one though... weird thing)