#1 is false Crazy. If the bomb explodes you get 1400, if it’s planted and defused you get 800 based on the plant.
#2 is completely false. The damage the m4 does is based on whether or not you have a helmet. No M4 will kill you in 1 bullet if you have a helmet 
AK will regardless of Helmet or not.
#3 Lucky is terrid with all guns besides Awp/Deeg
#4 and people have already answered this question
done to doneski