I was thinking, what if Loki has been playing everyone? Maybe he has that philosphy that killing some to save more is good?
So then maybe first he tried to kill all the FrostGiants to avoid a war with Asguard, then after Thor 1 he found out about Thanos and gained his trust including one of the gems, (the staff), then he traveled to earth to create some kind of protection against Thanos, he found information about the Avengers initiative, since he can be invisible and teleport and stuff with magic as seen in Thor 1, he also found out that it had been scraped which we found out in the Avengers, so in order to create the Avengers he played the part of a villain and killed people in order to convince them of the need for the Avengers and to bring them together - on purpose.
Now he has killed Odin and become King of Asgard, but not because he just wants to rule but because this allows him more power to defend people against Thanos.
Maybe he ruined things for Thor in order to make him more mature so that Asguard would not have a foolish King.
So then maybe first he tried to kill all the FrostGiants to avoid a war with Asguard, then after Thor 1 he found out about Thanos and gained his trust including one of the gems, (the staff), then he traveled to earth to create some kind of protection against Thanos, he found information about the Avengers initiative, since he can be invisible and teleport and stuff with magic as seen in Thor 1, he also found out that it had been scraped which we found out in the Avengers, so in order to create the Avengers he played the part of a villain and killed people in order to convince them of the need for the Avengers and to bring them together - on purpose.
Now he has killed Odin and become King of Asgard, but not because he just wants to rule but because this allows him more power to defend people against Thanos.
Maybe he ruined things for Thor in order to make him more mature so that Asguard would not have a foolish King.